diff --git a/Ghidra/Features/Base/src/main/help/help/topics/DataTypeEditors/StructureEditor.htm b/Ghidra/Features/Base/src/main/help/help/topics/DataTypeEditors/StructureEditor.htm
index ddbb78a6f7..9a5dd24ece 100644
--- a/Ghidra/Features/Base/src/main/help/help/topics/DataTypeEditors/StructureEditor.htm
+++ b/Ghidra/Features/Base/src/main/help/help/topics/DataTypeEditors/StructureEditor.htm
@@ -179,14 +179,12 @@
     <H3>Unaligned Structures</H3>
 
     <BLOCKQUOTE>
-      <P>When a structure is unaligned, with the exception of bitfields, each component immediately 
-      follows the one before it. In
-      other words no automatic alignment or padding occurs. Unaligned structures can contain 
-      Unaligned structures should be used to position components with known data
-      types at specific offsets within the structure. Therefore the structure editor tries to
-      prevent defined components (those other than Undefined bytes) from accidentally being moved
-      to a different offset when performing operations like drag and drop, although undefined bytes
-      may be consumed. <BR>
+      <P>When a structure is unaligned, with the exception of bitfields, each component shown within 
+      the editor immediately follows the one before it. In other words, no automatic alignment or padding occurs. 
+      Unaligned structures may be used to position components with known data
+      types at specific offsets within a structure. Therefore, when editing an unaligned structure,
+      the structure editor attempts to prevent defined components from moving
+      to a different offset when performing operations like drag and drop which may consume undefined bytes. <BR>
       </P>
 
       <DIV style="text-align: center; margin-top: 10px;">
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/DataTypeManagerDB.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/DataTypeManagerDB.java
index 94552ee191..327aa91932 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/DataTypeManagerDB.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/DataTypeManagerDB.java
@@ -812,7 +812,7 @@ abstract public class DataTypeManagerDB implements DataTypeManager {
 		}
 		finally {
 			if (isResolveCacheOwner) {
-				flushResolveCacheAndClearQueue();
+				flushResolveQueue(true);
 			}
 			if (isEquivalenceCacheOwner) {
 				clearEquivalenceCache();
@@ -1142,15 +1142,26 @@ abstract public class DataTypeManagerDB implements DataTypeManager {
 		lock.acquire();
 		boolean isEquivalenceCacheOwner = activateEquivalenceCache();
 		boolean isResolveCacheOwner = activateResolveCache();
+		// TODO: extended hold time on lock may cause the GUI to become
+		// unresponsive.  Consider releasing lock between resolves, although
+		// this exposes risk of having active resolve queue/cache without lock
 		try {
+			monitor.setMessage("Adding datatypes...");
+			monitor.setMaximum(dataTypes.size());
+			monitor.setProgress(0);
+			int i = 0;
 			for (DataType dt : dataTypes) {
 				monitor.checkCanceled();
 				resolve(dt, handler);
+				if (isResolveCacheOwner) {
+					flushResolveQueue(false);
+				}
+				monitor.setProgress(++i);
 			}
 		}
 		finally {
 			if (isResolveCacheOwner) {
-				flushResolveCacheAndClearQueue();
+				flushResolveQueue(true);
 			}
 			if (isEquivalenceCacheOwner) {
 				clearEquivalenceCache();
@@ -3764,19 +3775,17 @@ abstract public class DataTypeManagerDB implements DataTypeManager {
 	/**
 	 * Activate resolveCache and associated resolveQueue if not already active. If
 	 * this method returns true caller is responsible for flushing resolveQueue and
-	 * invoking {@link #flushResolveCacheAndClearQueue(DataTypeConflictHandler)}
-	 * when resolve. For each completed resolve
-	 * {@link #cacheResolvedDataType(DataType, DataType)} should be called.
+	 * invoking {@link #flushResolveQueue(boolean)} when resolve complete. 
+	 * For each completed resolve {@link #cacheResolvedDataType(DataType, DataType)} 
+	 * should be invoked.
 	 * 
-	 * @return true if resolveCache and resolveQueue activated else false if
-	 *         previously activated.
+	 * @return true if resolveCache activated else false if already active.
 	 */
 	boolean activateResolveCache() {
 		if (resolveCache != null) {
 			return false;
 		}
 		resolveCache = new IdentityHashMap<>();
-		resolveQueue = new TreeSet<>();
 		return true;
 	}
 
@@ -3788,10 +3797,19 @@ abstract public class DataTypeManagerDB implements DataTypeManager {
 	 */
 	void queuePostResolve(DataTypeDB resolvedDt, DataType definitionDt) {
 		resolvedDt.resolving = true;
+		if (resolveQueue == null) {
+			resolveQueue = new TreeSet<>();
+		}
 		resolveQueue.add(new ResolvePair(resolvedDt, definitionDt));
 	}
 
-	void flushResolveCacheAndClearQueue() {
+	void flushResolveQueue(boolean deactivateCache) {
+		if (resolveQueue == null) {
+			if (deactivateCache) {
+				resolveCache = null;
+			}
+			return;
+		}
 		DataTypeConflictHandler handler = getDependencyConflictHandler();
 		while (!resolveQueue.isEmpty()) {
 			ResolvePair resolvePair = resolveQueue.pollFirst();
@@ -3805,8 +3823,10 @@ abstract public class DataTypeManagerDB implements DataTypeManager {
 				resolvedDt.pointerPostResolveRequired = false;
 			}
 		}
-		resolveCache = null;
 		resolveQueue = null;
+		if (deactivateCache) {
+			resolveCache = null;
+		}
 	}
 
 	private DataType getCachedResolve(DataType dt) {
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/StructureDB.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/StructureDB.java
index afb5024090..ba73acb18b 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/StructureDB.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/StructureDB.java
@@ -1168,7 +1168,7 @@ class StructureDB extends CompositeDB implements Structure {
 		}
 		finally {
 			if (isResolveCacheOwner) {
-				dataMgr.flushResolveCacheAndClearQueue();
+				dataMgr.flushResolveQueue(true);
 			}
 			lock.release();
 		}
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/UnionDB.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/UnionDB.java
index 1c3bb0faef..34bb985bb2 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/UnionDB.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/database/data/UnionDB.java
@@ -257,7 +257,7 @@ class UnionDB extends CompositeDB implements Union {
 		}
 		finally {
 			if (isResolveCacheOwner) {
-				dataMgr.flushResolveCacheAndClearQueue();
+				dataMgr.flushResolveQueue(true);
 			}
 			lock.release();
 		}
diff --git a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/DataTypeManager.java b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/DataTypeManager.java
index 98a51620eb..18cb06dbc4 100644
--- a/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/DataTypeManager.java
+++ b/Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/DataTypeManager.java
@@ -101,6 +101,9 @@ public interface DataTypeManager {
 	 * Sequentially adds a collection of datatypes to this data manager.  
 	 * This method provides the added benefit of equivalence caching
 	 * for improved performance.
+	 * <br>
+	 * WARNING: This is an experimental method whoose use may cause the GUI and
+	 * task monitor to become unresponsive due to extended hold times on the manager lock.
 	 * @param dataTypes collection of datatypes
 	 * @param handler conflict handler
 	 * @param monitor task monitor