diff --git a/bndtools.core/src/bndtools/Plugin.java b/bndtools.core/src/bndtools/Plugin.java
index c2042a0bb9..d4fb57ab3b 100644
--- a/bndtools.core/src/bndtools/Plugin.java
+++ b/bndtools.core/src/bndtools/Plugin.java
@@ -70,7 +70,7 @@ public void start(BundleContext context) throws Exception {
 		plugin = this;
 		this.bundleContext = context;
 
-		scheduler = Executors.newScheduledThreadPool(1);
+		scheduler = Executors.newScheduledThreadPool(4);
 
 		bndActivator = new Activator();
 		bndActivator.start(context);
diff --git a/bndtools.core/src/bndtools/explorer/BndtoolsExplorer.java b/bndtools.core/src/bndtools/explorer/BndtoolsExplorer.java
index eeb799fff2..22b1459791 100644
--- a/bndtools.core/src/bndtools/explorer/BndtoolsExplorer.java
+++ b/bndtools.core/src/bndtools/explorer/BndtoolsExplorer.java
@@ -336,9 +336,11 @@ private void updateTreeViewer() {
 		if (!installed) {
 			installed = true;
 			installFilter();
+			model.filterDirty.set(true);
 		}
 
-		getTreeViewer().refresh();
+		if (model.filterDirty.getAndSet(false))
+			getTreeViewer().refresh();
 	}
 
 	private void installFilter() {
diff --git a/bndtools.core/src/bndtools/explorer/Model.java b/bndtools.core/src/bndtools/explorer/Model.java
index 7174eb4439..155ac29f6b 100644
--- a/bndtools.core/src/bndtools/explorer/Model.java
+++ b/bndtools.core/src/bndtools/explorer/Model.java
@@ -24,6 +24,7 @@ class Model {
 	String					message	= "initializing workspace";
 	int						severity;
 	String					filterText;
+	final AtomicBoolean		filterDirty	= new AtomicBoolean(false);
 	final List<Runnable>	updates	= new ArrayList<>();
 	final AtomicBoolean		dirty	= new AtomicBoolean(false);
 	final Set<IProject>		pinned	= new HashSet<>();
@@ -48,6 +49,7 @@ void setFilterText(String value) {
 			glob = null;
 		else
 			glob = new Glob(value);
+		filterDirty.set(true);
 		update();
 	}
 
@@ -77,6 +79,7 @@ void updateMessage() {
 	void setSeverity(int severity) {
 		if (this.severity != severity) {
 			this.severity = severity;
+			filterDirty.set(true);
 			update();
 		}
 	}
@@ -84,7 +87,7 @@ void setSeverity(int severity) {
 	private String getPrompt(Workspace ws) {
 		try {
 			if (prompt == null || prompt.isEmpty())
-				prompt = "<b>${basename;${workspace}}</b> ${def;Bundle-Version} <a href='prefs'>change macro def</a>";
+				prompt = "<b>${basename;${workspace}}</b> ${def;Bundle-Version} <a href='prefs'>[?]</a>";
 			else if ("-".equals(prompt))
 				return "";
 
@@ -113,16 +116,6 @@ void update() {
 	 * This runs async on the display thread.
 	 */
 	private void update0() {
-		try {
-			// coalesce some more updates on
-			// the worker thread(s).
-			Thread.sleep(50);
-		} catch (InterruptedException e) {
-			Thread.currentThread()
-				.interrupt();
-			return;
-		}
-
 		if (dirty.getAndSet(false)) {
 			updates.forEach(Runnable::run);
 		}
@@ -138,6 +131,7 @@ void doPin() {
 		} else {
 			pinned.add(p);
 		}
+		filterDirty.set(true);
 		update();
 	}