diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7272a15..1edfa6d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,11 @@
 # UI Changelog
 
+## 2023-01-20
+
+- Removed "Use selection as mask" option; Using the selection to mask generated images is now default behaviour.
+- Added "Add transparency mask" option; Choose to mask generated images by adding transparency mask, or directly flatten/crop image.
+- Top paintlayer will now be set as active layer when generation is complete.
+
 ## 2022-12-28
 
 - Added "Alt Dock Behaviour" under "SD Plugin Config".
diff --git a/README.md b/README.md
index 3942f11..5d02ac8 100644
--- a/README.md
+++ b/README.md
@@ -103,6 +103,12 @@ A: Unfortunately no, all plugins so far have different APIs. The official API is
 
 See [CHANGELOG.md](./CHANGELOG.md) for the full changelog.
 
+### 2023-01-20
+
+- Removed "Use selection as mask" option; Using the selection to mask generated images is now default behaviour.
+- Added "Add transparency mask" option; Choose to mask generated images by adding transparency mask, or directly flatten/crop image.
+- Top paintlayer will now be set as active layer when generation is complete.
+
 ### 2022-12-28
 
 - Added "Alt Dock Behaviour" under "SD Plugin Config".
diff --git a/frontends/krita/krita_diff/defaults.py b/frontends/krita/krita_diff/defaults.py
index e9df043..fa48c7f 100644
--- a/frontends/krita/krita_diff/defaults.py
+++ b/frontends/krita/krita_diff/defaults.py
@@ -21,8 +21,7 @@ ETA_REFRESH_INTERVAL = 1000  # 1 second between eta refresh
 CFG_FOLDER = "krita"  # which folder in ~/.config to store config
 CFG_NAME = "krita_diff_plugin"  # name of config file
 EXT_CFG_NAME = "krita_diff_plugin_scripts"  # name of config file
-# selection mask can only be added after image is added, so timeout is needed
-ADD_MASK_TIMEOUT = 200
+ADD_MASK_TIMEOUT = 50
 THREADED = True
 ROUTE_PREFIX = "/sdapi/interpause/"
 OFFICIAL_ROUTE_PREFIX = "/sdapi/v1/"
diff --git a/frontends/krita/krita_diff/pages/config.py b/frontends/krita/krita_diff/pages/config.py
index 429bfe1..ac2aad9 100644
--- a/frontends/krita/krita_diff/pages/config.py
+++ b/frontends/krita/krita_diff/pages/config.py
@@ -31,7 +31,7 @@ class ConfigPage(QWidget):
             script.cfg, "just_use_yaml", "(unrecommended) Ignore settings"
         )
         self.create_mask_layer = QCheckBox(
-            script.cfg, "create_mask_layer", "Use selection as mask"
+            script.cfg, "create_mask_layer", "Add transparency mask"
         )
         self.save_temp_images = QCheckBox(
             script.cfg, "save_temp_images", "Save images for debug"
diff --git a/frontends/krita/krita_diff/script.py b/frontends/krita/krita_diff/script.py
index bccd5f8..ebccbe1 100644
--- a/frontends/krita/krita_diff/script.py
+++ b/frontends/krita/krita_diff/script.py
@@ -335,22 +335,54 @@ class Script(QObject):
     def transparency_mask_inserter(self):
         """Mask out extra regions due to adjust_selection()."""
         orig_selection = self.selection.duplicate() if self.selection else None
+        create_mask = self.cfg("create_mask_layer", bool)
 
-        def add_mask(layers):
-            self.doc.waitForDone()
-            cur_selection = self.selection
-            cur_layer = self.doc.activeNode()
-            for layer in layers:
-                self.doc.setActiveNode(layer)
-                self.doc.setSelection(orig_selection)
-                self.app.action("add_new_transparency_mask").trigger()
-            self.doc.setSelection(cur_selection)  # reset to current selection
-            self.doc.setActiveNode(cur_layer)  # reset to current layer
+        add_mask_action = self.app.action("add_new_transparency_mask")
+        merge_mask_action = self.app.action("flatten_layer")
 
-        def trigger_mask_adding(layers):
-            if self.cfg("create_mask_layer", bool):
-                # need timeout to ensure layer exists first else crash
-                QTimer.singleShot(ADD_MASK_TIMEOUT, lambda: add_mask(layers))
+        # This function is recursive to workaround race conditions when calling Krita's actions
+        def add_mask(layers: list, cur_selection):
+            if len(layers) < 1:
+                self.doc.setSelection(cur_selection)  # reset to current selection
+                return
+            layer = layers.pop()
+
+            orig_visible = layer.visible()
+            orig_name = layer.name()
+
+            def restore():
+                # assume newly flattened layer is active
+                result = self.doc.activeNode()
+                result.setVisible(orig_visible)
+                result.setName(orig_name)
+
+                add_mask(layers, cur_selection)
+
+            layer.setVisible(True)
+            self.doc.setActiveNode(layer)
+            self.doc.setSelection(orig_selection)
+            add_mask_action.trigger()
+
+            if create_mask:
+                # collapse transparency mask by default
+                layer.setCollapsed(True)
+                layer.setVisible(orig_visible)
+                QTimer.singleShot(
+                    ADD_MASK_TIMEOUT, lambda: add_mask(layers, cur_selection)
+                )
+            else:
+                # flatten transparency mask into layer
+                merge_mask_action.trigger()
+                QTimer.singleShot(ADD_MASK_TIMEOUT, lambda: restore())
+
+        def trigger_mask_adding(layers: list):
+            layers = layers[::-1]  # causes final active layer to be the top one
+
+            def handle_mask():
+                cur_selection = self.selection.duplicate() if self.selection else None
+                add_mask(layers, cur_selection)
+
+            QTimer.singleShot(ADD_MASK_TIMEOUT, lambda: handle_mask())
 
         return trigger_mask_adding