diff --git a/java/src/com/android/inputmethod/latin/LatinIME.java b/java/src/com/android/inputmethod/latin/LatinIME.java
index d590d66..fa9f466 100644
--- a/java/src/com/android/inputmethod/latin/LatinIME.java
+++ b/java/src/com/android/inputmethod/latin/LatinIME.java
@@ -1857,6 +1857,11 @@
             }
             mConnection.setComposingText(getTextWithUnderline(mWordComposer.getTypedWord()), 1);
             mHandler.postUpdateSuggestionStrip();
+            if (!mWordComposer.isComposingWord()) {
+                // If we just removed the last character, auto-caps mode may have changed so we
+                // need to re-evaluate.
+                mKeyboardSwitcher.updateShiftState();
+            }
         } else {
             final SettingsValues currentSettings = mSettings.getCurrent();
             if (mLastComposedWord.canRevertCommit()) {
@@ -1916,6 +1921,8 @@
                     // This should never happen.
                     Log.e(TAG, "Backspace when we don't know the selection position");
                 }
+                final int lengthToDelete = Character.isSupplementaryCodePoint(
+                        mConnection.getCodePointBeforeCursor()) ? 2 : 1;
                 if (mAppWorkAroundsUtils.isBeforeJellyBean()) {
                     // Backward compatibility mode. Before Jelly bean, the keyboard would simulate
                     // a hardware keyboard event on pressing enter or delete. This is bad for many
@@ -1923,15 +1930,18 @@
                     // relying on this behavior so we continue to support it for older apps.
                     sendDownUpKeyEventForBackwardCompatibility(KeyEvent.KEYCODE_DEL);
                 } else {
-                    mConnection.deleteSurroundingText(1, 0);
+                    mConnection.deleteSurroundingText(lengthToDelete, 0);
                 }
                 if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
-                    ResearchLogger.latinIME_handleBackspace(1, true /* shouldUncommitLogUnit */);
+                    ResearchLogger.latinIME_handleBackspace(lengthToDelete,
+                            true /* shouldUncommitLogUnit */);
                 }
                 if (mDeleteCount > DELETE_ACCELERATE_AT) {
-                    mConnection.deleteSurroundingText(1, 0);
+                    final int lengthToDeleteAgain = Character.isSupplementaryCodePoint(
+                            mConnection.getCodePointBeforeCursor()) ? 2 : 1;
+                    mConnection.deleteSurroundingText(lengthToDeleteAgain, 0);
                     if (ProductionFlag.USES_DEVELOPMENT_ONLY_DIAGNOSTICS) {
-                        ResearchLogger.latinIME_handleBackspace(1,
+                        ResearchLogger.latinIME_handleBackspace(lengthToDeleteAgain,
                                 true /* shouldUncommitLogUnit */);
                     }
                 }
@@ -1939,6 +1949,8 @@
             if (currentSettings.isSuggestionsRequested(mDisplayOrientation)) {
                 restartSuggestionsOnWordBeforeCursorIfAtEndOfWord();
             }
+            // We just removed a character. We need to update the auto-caps state.
+            mKeyboardSwitcher.updateShiftState();
         }
     }
 
@@ -2725,17 +2737,6 @@
                 break;
             }
         }
-
-        if (Constants.CODE_DELETE == primaryCode) {
-            // This is a stopgap solution to avoid leaving a high surrogate alone in a text view.
-            // In the future, we need to deprecate deteleSurroundingText() and have a surrogate
-            // pair-friendly way of deleting characters in InputConnection.
-            // TODO: use getCodePointBeforeCursor instead to improve performance
-            final CharSequence lastChar = mConnection.getTextBeforeCursor(1, 0);
-            if (!TextUtils.isEmpty(lastChar) && Character.isHighSurrogate(lastChar.charAt(0))) {
-                mConnection.deleteSurroundingText(1, 0);
-            }
-        }
     }
 
     // Hooks for hardware keyboard
diff --git a/native/jni/src/suggest/core/dicnode/dic_node_proximity_filter.h b/native/jni/src/suggest/core/dicnode/dic_node_proximity_filter.h
deleted file mode 100644
index c7ab571..0000000
--- a/native/jni/src/suggest/core/dicnode/dic_node_proximity_filter.h
+++ /dev/null
@@ -1,58 +0,0 @@
-/*
- * Copyright (C) 2013 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-#ifndef LATINIME_DIC_NODE_PROXIMITY_FILTER_H
-#define LATINIME_DIC_NODE_PROXIMITY_FILTER_H
-
-#include "defines.h"
-#include "suggest/core/layout/proximity_info_state.h"
-#include "suggest/core/layout/proximity_info_utils.h"
-#include "suggest/core/policy/dictionary_structure_with_buffer_policy.h"
-
-namespace latinime {
-
-class DicNodeProximityFilter : public DictionaryStructureWithBufferPolicy::NodeFilter {
- public:
-    DicNodeProximityFilter(const ProximityInfoState *const pInfoState,
-            const int pointIndex, const bool exactOnly)
-            : mProximityInfoState(pInfoState), mPointIndex(pointIndex), mExactOnly(exactOnly) {}
-
-    bool isFilteredOut(const int codePoint) const {
-        return !isProximityCodePoint(codePoint);
-    }
-
- private:
-    DISALLOW_IMPLICIT_CONSTRUCTORS(DicNodeProximityFilter);
-
-    const ProximityInfoState *const mProximityInfoState;
-    const int mPointIndex;
-    const bool mExactOnly;
-
-    // TODO: Move to proximity info state
-    bool isProximityCodePoint(const int codePoint) const {
-        if (!mProximityInfoState) {
-            return true;
-        }
-        if (mExactOnly) {
-            return mProximityInfoState->getPrimaryCodePointAt(mPointIndex) == codePoint;
-        }
-        const ProximityType matchedId = mProximityInfoState->getProximityType(
-                mPointIndex, codePoint, true /* checkProximityChars */);
-        return ProximityInfoUtils::isMatchOrProximityChar(matchedId);
-    }
-};
-} // namespace latinime
-#endif // LATINIME_DIC_NODE_PROXIMITY_FILTER_H
diff --git a/native/jni/src/suggest/core/dicnode/dic_node_utils.cpp b/native/jni/src/suggest/core/dicnode/dic_node_utils.cpp
index 150eb67..bb54e60 100644
--- a/native/jni/src/suggest/core/dicnode/dic_node_utils.cpp
+++ b/native/jni/src/suggest/core/dicnode/dic_node_utils.cpp
@@ -19,7 +19,6 @@
 #include <cstring>
 
 #include "suggest/core/dicnode/dic_node.h"
-#include "suggest/core/dicnode/dic_node_proximity_filter.h"
 #include "suggest/core/dicnode/dic_node_vector.h"
 #include "suggest/core/dictionary/multi_bigram_map.h"
 #include "suggest/core/dictionary/probability_utils.h"
@@ -52,38 +51,16 @@
 ///////////////////////////////////
 // Traverse node expansion utils //
 ///////////////////////////////////
-
-/* static */ void DicNodeUtils::createAndGetPassingChildNode(DicNode *dicNode,
-        const DicNodeProximityFilter *const childrenFilter,
-        DicNodeVector *childDicNodes) {
-    // Passing multiple chars node. No need to traverse child
-    const int codePoint = dicNode->getNodeTypedCodePoint();
-    const int baseLowerCaseCodePoint = CharUtils::toBaseLowerCase(codePoint);
-    if (!childrenFilter->isFilteredOut(codePoint)
-            || CharUtils::isIntentionalOmissionCodePoint(baseLowerCaseCodePoint)) {
-        childDicNodes->pushPassingChild(dicNode);
-    }
-}
-
 /* static */ void DicNodeUtils::getAllChildDicNodes(DicNode *dicNode,
         const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
         DicNodeVector *childDicNodes) {
-    getProximityChildDicNodes(dicNode, dictionaryStructurePolicy, 0, 0, false, childDicNodes);
-}
-
-/* static */ void DicNodeUtils::getProximityChildDicNodes(DicNode *dicNode,
-        const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
-        const ProximityInfoState *pInfoState, const int pointIndex, bool exactOnly,
-        DicNodeVector *childDicNodes) {
     if (dicNode->isTotalInputSizeExceedingLimit()) {
         return;
     }
-    const DicNodeProximityFilter childrenFilter(pInfoState, pointIndex, exactOnly);
     if (!dicNode->isLeavingNode()) {
-        DicNodeUtils::createAndGetPassingChildNode(dicNode, &childrenFilter, childDicNodes);
+        childDicNodes->pushPassingChild(dicNode);
     } else {
-        dictionaryStructurePolicy->createAndGetAllChildNodes(dicNode,
-                &childrenFilter, childDicNodes);
+        dictionaryStructurePolicy->createAndGetAllChildNodes(dicNode, childDicNodes);
     }
 }
 
diff --git a/native/jni/src/suggest/core/dicnode/dic_node_utils.h b/native/jni/src/suggest/core/dicnode/dic_node_utils.h
index 8dc984f..3fb351a 100644
--- a/native/jni/src/suggest/core/dicnode/dic_node_utils.h
+++ b/native/jni/src/suggest/core/dicnode/dic_node_utils.h
@@ -24,10 +24,8 @@
 namespace latinime {
 
 class DicNode;
-class DicNodeProximityFilter;
 class DicNodeVector;
 class DictionaryStructureWithBufferPolicy;
-class ProximityInfoState;
 class MultiBigramMap;
 
 class DicNodeUtils {
@@ -47,11 +45,6 @@
     static float getBigramNodeImprobability(
             const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
             const DicNode *const node, MultiBigramMap *const multiBigramMap);
-    // TODO: Move to private
-    static void getProximityChildDicNodes(DicNode *dicNode,
-            const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
-            const ProximityInfoState *pInfoState, const int pointIndex, bool exactOnly,
-            DicNodeVector *childDicNodes);
 
  private:
     DISALLOW_IMPLICIT_CONSTRUCTORS(DicNodeUtils);
@@ -61,8 +54,6 @@
     static int getBigramNodeProbability(
             const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
             const DicNode *const node, MultiBigramMap *multiBigramMap);
-    static void createAndGetPassingChildNode(DicNode *dicNode,
-            const DicNodeProximityFilter *const childrenFilter, DicNodeVector *childDicNodes);
 };
 } // namespace latinime
 #endif // LATINIME_DIC_NODE_UTILS_H
diff --git a/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h b/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
index 1b34f03..37daef9 100644
--- a/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
+++ b/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
@@ -33,25 +33,12 @@
  */
 class DictionaryStructureWithBufferPolicy {
  public:
-    // This provides a filtering method for filtering new node.
-    class NodeFilter {
-     public:
-        virtual bool isFilteredOut(const int codePoint) const = 0;
-
-     protected:
-        NodeFilter() {}
-        virtual ~NodeFilter() {}
-
-     private:
-        DISALLOW_COPY_AND_ASSIGN(NodeFilter);
-    };
-
     virtual ~DictionaryStructureWithBufferPolicy() {}
 
     virtual int getRootPosition() const = 0;
 
     virtual void createAndGetAllChildNodes(const DicNode *const dicNode,
-            const NodeFilter *const nodeFilter, DicNodeVector *const childDicNodes) const = 0;
+            DicNodeVector *const childDicNodes) const = 0;
 
     virtual int getCodePointsAndProbabilityAndReturnCodePointCount(
             const int nodePos, const int maxCodePointCount, int *const outCodePoints,
diff --git a/native/jni/src/suggest/core/suggest.cpp b/native/jni/src/suggest/core/suggest.cpp
index 3b77227..7d8dd21 100644
--- a/native/jni/src/suggest/core/suggest.cpp
+++ b/native/jni/src/suggest/core/suggest.cpp
@@ -456,7 +456,6 @@
         Weighting::addCostAndForwardInputIndex(WEIGHTING, CT_OMISSION, traverseSession,
                 dicNode, childDicNode, 0 /* multiBigramMap */);
         weightChildNode(traverseSession, childDicNode);
-
         if (!TRAVERSAL->isPossibleOmissionChildNode(traverseSession, dicNode, childDicNode)) {
             continue;
         }
@@ -472,11 +471,14 @@
         DicNode *dicNode) const {
     const int16_t pointIndex = dicNode->getInputIndex(0);
     DicNodeVector childDicNodes;
-    DicNodeUtils::getProximityChildDicNodes(dicNode,
-            traverseSession->getDictionaryStructurePolicy(),
-            traverseSession->getProximityInfoState(0), pointIndex + 1, true, &childDicNodes);
+    DicNodeUtils::getAllChildDicNodes(dicNode, traverseSession->getDictionaryStructurePolicy(),
+            &childDicNodes);
     const int size = childDicNodes.getSizeAndLock();
     for (int i = 0; i < size; i++) {
+        if (traverseSession->getProximityInfoState(0)->getPrimaryCodePointAt(pointIndex + 1)
+                != childDicNodes[i]->getNodeCodePoint()) {
+            continue;
+        }
         DicNode *const childDicNode = childDicNodes[i];
         Weighting::addCostAndForwardInputIndex(WEIGHTING, CT_INSERTION, traverseSession,
                 dicNode, childDicNode, 0 /* multiBigramMap */);
@@ -491,19 +493,29 @@
         DicNode *dicNode) const {
     const int16_t pointIndex = dicNode->getInputIndex(0);
     DicNodeVector childDicNodes1;
-    DicNodeUtils::getProximityChildDicNodes(dicNode,
-            traverseSession->getDictionaryStructurePolicy(),
-            traverseSession->getProximityInfoState(0), pointIndex + 1, false, &childDicNodes1);
+    DicNodeUtils::getAllChildDicNodes(dicNode, traverseSession->getDictionaryStructurePolicy(),
+            &childDicNodes1);
     const int childSize1 = childDicNodes1.getSizeAndLock();
     for (int i = 0; i < childSize1; i++) {
+        const ProximityType matchedId1 = traverseSession->getProximityInfoState(0)
+                ->getProximityType(pointIndex + 1, childDicNodes1[i]->getNodeCodePoint(),
+                        true /* checkProximityChars */);
+        if (!ProximityInfoUtils::isMatchOrProximityChar(matchedId1)) {
+            continue;
+        }
         if (childDicNodes1[i]->hasChildren()) {
             DicNodeVector childDicNodes2;
-            DicNodeUtils::getProximityChildDicNodes(
-                    childDicNodes1[i], traverseSession->getDictionaryStructurePolicy(),
-                    traverseSession->getProximityInfoState(0), pointIndex, false, &childDicNodes2);
+            DicNodeUtils::getAllChildDicNodes(childDicNodes1[i],
+                    traverseSession->getDictionaryStructurePolicy(), &childDicNodes2);
             const int childSize2 = childDicNodes2.getSizeAndLock();
             for (int j = 0; j < childSize2; j++) {
                 DicNode *const childDicNode2 = childDicNodes2[j];
+                const ProximityType matchedId2 = traverseSession->getProximityInfoState(0)
+                        ->getProximityType(pointIndex, childDicNode2->getNodeCodePoint(),
+                                true /* checkProximityChars */);
+                if (!ProximityInfoUtils::isMatchOrProximityChar(matchedId2)) {
+                    continue;
+                }
                 Weighting::addCostAndForwardInputIndex(WEIGHTING, CT_TRANSPOSITION,
                         traverseSession, childDicNodes1[i], childDicNode2, 0 /* multiBigramMap */);
                 processExpandedDicNode(traverseSession, childDicNode2);
diff --git a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.cpp
index 7d3b2e2..cca8010 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.cpp
@@ -29,7 +29,7 @@
 const int DynamicPatriciaTriePolicy::MAX_CHILD_COUNT_TO_AVOID_INFINITE_LOOP = 100000;
 
 void DynamicPatriciaTriePolicy::createAndGetAllChildNodes(const DicNode *const dicNode,
-        const NodeFilter *const nodeFilter, DicNodeVector *const childDicNodes) const {
+        DicNodeVector *const childDicNodes) const {
     if (!dicNode->hasChildren()) {
         return;
     }
@@ -52,8 +52,8 @@
         for (int i = 0; i < childCount; i++) {
             nodeReader.fetchNodeInfoFromBufferAndGetNodeCodePoints(nextPos, MAX_WORD_LENGTH,
                     mergedNodeCodePoints);
-            if (!nodeReader.isDeleted() && !nodeFilter->isFilteredOut(mergedNodeCodePoints[0])) {
-                // Push child node when the node is not deleted and not filtered out.
+            if (!nodeReader.isDeleted()) {
+                // Push child node when the node is not a deleted node.
                 childDicNodes->pushLeavingChild(dicNode, nodeReader.getNodePos(),
                         nodeReader.getChildrenPos(), nodeReader.getProbability(),
                         nodeReader.isTerminal(), nodeReader.hasChildren(),
diff --git a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.h
index 56475b1..ad8911c 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/dynamic_patricia_trie_policy.h
@@ -43,7 +43,7 @@
     }
 
     void createAndGetAllChildNodes(const DicNode *const dicNode,
-            const NodeFilter *const nodeFilter, DicNodeVector *const childDicNodes) const;
+            DicNodeVector *const childDicNodes) const;
 
     int getCodePointsAndProbabilityAndReturnCodePointCount(
             const int terminalNodePos, const int maxCodePointCount, int *const outCodePoints,
diff --git a/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.cpp
index 8ce2b3e..3e664a2 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.cpp
@@ -26,7 +26,7 @@
 namespace latinime {
 
 void PatriciaTriePolicy::createAndGetAllChildNodes(const DicNode *const dicNode,
-        const NodeFilter *const nodeFilter, DicNodeVector *const childDicNodes) const {
+        DicNodeVector *const childDicNodes) const {
     if (!dicNode->hasChildren()) {
         return;
     }
@@ -34,7 +34,7 @@
     const int childCount = PatriciaTrieReadingUtils::getGroupCountAndAdvancePosition(
             mDictRoot, &nextPos);
     for (int i = 0; i < childCount; i++) {
-        nextPos = createAndGetLeavingChildNode(dicNode, nextPos, nodeFilter, childDicNodes);
+        nextPos = createAndGetLeavingChildNode(dicNode, nextPos, childDicNodes);
     }
 }
 
@@ -116,8 +116,7 @@
 }
 
 int PatriciaTriePolicy::createAndGetLeavingChildNode(const DicNode *const dicNode,
-        const int nodePos,  const NodeFilter *const childrenFilter,
-        DicNodeVector *childDicNodes) const {
+        const int nodePos, DicNodeVector *childDicNodes) const {
     int pos = nodePos;
     const PatriciaTrieReadingUtils::NodeFlags flags =
             PatriciaTrieReadingUtils::getFlagsAndAdvancePosition(mDictRoot, &pos);
@@ -136,14 +135,12 @@
     if (PatriciaTrieReadingUtils::hasBigrams(flags)) {
         getBigramsStructurePolicy()->skipAllBigrams(&pos);
     }
-    if (!childrenFilter->isFilteredOut(mergedNodeCodePoints[0])) {
-        childDicNodes->pushLeavingChild(dicNode, nodePos, childrenPos, probability,
-                PatriciaTrieReadingUtils::isTerminal(flags),
-                PatriciaTrieReadingUtils::hasChildrenInFlags(flags),
-                PatriciaTrieReadingUtils::isBlacklisted(flags) ||
-                        PatriciaTrieReadingUtils::isNotAWord(flags),
-                mergedNodeCodePointCount, mergedNodeCodePoints);
-    }
+    childDicNodes->pushLeavingChild(dicNode, nodePos, childrenPos, probability,
+            PatriciaTrieReadingUtils::isTerminal(flags),
+            PatriciaTrieReadingUtils::hasChildrenInFlags(flags),
+            PatriciaTrieReadingUtils::isBlacklisted(flags) ||
+                    PatriciaTrieReadingUtils::isNotAWord(flags),
+            mergedNodeCodePointCount, mergedNodeCodePoints);
     return pos;
 }
 
diff --git a/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.h
index bebe1bf..2e34480 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/patricia_trie_policy.h
@@ -43,7 +43,7 @@
     }
 
     void createAndGetAllChildNodes(const DicNode *const dicNode,
-            const NodeFilter *const nodeFilter, DicNodeVector *const childDicNodes) const;
+            DicNodeVector *const childDicNodes) const;
 
     int getCodePointsAndProbabilityAndReturnCodePointCount(
             const int terminalNodePos, const int maxCodePointCount, int *const outCodePoints,
@@ -79,7 +79,7 @@
     const ShortcutListPolicy mShortcutListPolicy;
 
     int createAndGetLeavingChildNode(const DicNode *const dicNode, const int nodePos,
-            const NodeFilter *const nodeFilter, DicNodeVector *const childDicNodes) const;
+            DicNodeVector *const childDicNodes) const;
 };
 } // namespace latinime
 #endif // LATINIME_PATRICIA_TRIE_POLICY_H