diff --git a/jdaviz/configs/cubeviz/helper.py b/jdaviz/configs/cubeviz/helper.py
index c7206327cd..fce4f61b15 100644
--- a/jdaviz/configs/cubeviz/helper.py
+++ b/jdaviz/configs/cubeviz/helper.py
@@ -18,9 +18,11 @@ class Cubeviz(CubeConfigHelper, LineListMixin):
     _default_uncert_viewer_reference_name = "uncert-viewer"
     _default_flux_viewer_reference_name = "flux-viewer"
     _default_image_viewer_reference_name = "image-viewer"
+    _cube_viewer_default_label = _default_flux_viewer_reference_name
 
     _loaded_flux_cube = None
     _loaded_uncert_cube = None
+    _cube_viewer_cls = CubevizImageView
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
@@ -28,17 +30,6 @@ def __init__(self, *args, **kwargs):
         self.app.hub.subscribe(self, AddDataMessage,
                                handler=self._set_spectrum_x_axis)
 
-        self._update_slice_defaults()
-
-    def _update_slice_defaults(self):
-        available_plugins = [
-            tray_item['name'] for tray_item in self.app.state.tray_items
-        ]
-        if 'cube-slice' in available_plugins:
-            slice_plugin = self.app.get_tray_item_from_name('cube-slice')
-            slice_plugin._cube_viewer_default_label = self._default_flux_viewer_reference_name
-            slice_plugin._cube_viewer_cls = CubevizImageView
-
     def _set_spectrum_x_axis(self, msg):
         viewer = self.app.get_viewer(self._default_spectrum_viewer_reference_name)
         if msg.viewer_id != viewer.reference_id:
diff --git a/jdaviz/configs/cubeviz/plugins/slice/slice.py b/jdaviz/configs/cubeviz/plugins/slice/slice.py
index 88ab2995b2..7bb0e4c149 100644
--- a/jdaviz/configs/cubeviz/plugins/slice/slice.py
+++ b/jdaviz/configs/cubeviz/plugins/slice/slice.py
@@ -47,8 +47,6 @@ class Slice(PluginTemplateMixin):
     * ``show_value``
       Whether to show slice value in label to right of indicator.
     """
-    _cube_viewer_cls = (CubevizImageView, RampvizImageView)
-    _cube_viewer_default_label = None  # must be filled in by helper on initialization
 
     cube_viewer_exists = Bool(True).tag(sync=True)
 
@@ -105,6 +103,18 @@ def __init__(self, *args, **kwargs):
                                    handler=self._on_global_display_unit_changed)
         self._initialize_location()
 
+    @property
+    def _cube_viewer_default_label(self):
+        if hasattr(self.app, '_jdaviz_helper') and self.app._jdaviz_helper is not None:
+            return getattr(self.app._jdaviz_helper, '_cube_viewer_default_label')
+        return tuple()
+
+    @property
+    def _cube_viewer_cls(self):
+        if hasattr(self.app, '_jdaviz_helper') and self.app._jdaviz_helper is not None:
+            return getattr(self.app._jdaviz_helper, '_cube_viewer_cls')
+        return tuple()
+
     def _initialize_location(self, *args):
         # initialize value_unit (this has to wait until data is loaded to an existing
         # slice_indicator_viewer, so we'll keep trying until it is set - after that, changes
diff --git a/jdaviz/configs/rampviz/helper.py b/jdaviz/configs/rampviz/helper.py
index 2213f09d5e..4fb68c717a 100644
--- a/jdaviz/configs/rampviz/helper.py
+++ b/jdaviz/configs/rampviz/helper.py
@@ -14,25 +14,16 @@ class Rampviz(CubeConfigHelper):
     _default_group_viewer_reference_name = "group-viewer"
     _default_diff_viewer_reference_name = "diff-viewer"
     _default_integration_viewer_reference_name = "integration-viewer"
+    _cube_viewer_default_label = _default_group_viewer_reference_name
 
     _loaded_flux_cube = None
+    _cube_viewer_cls = RampvizImageView
 
     def __init__(self, *args, **kwargs):
         super().__init__(*args, **kwargs)
 
         self.cube_cache = {}
 
-        self._update_slice_defaults()
-
-    def _update_slice_defaults(self):
-        available_plugins = [
-            tray_item['name'] for tray_item in self.app.state.tray_items
-        ]
-        if 'cube-slice' in available_plugins:
-            slice_plugin = self.app.get_tray_item_from_name('cube-slice')
-            slice_plugin._cube_viewer_default_label = self._default_group_viewer_reference_name
-            slice_plugin._cube_viewer_cls = RampvizImageView
-
     def load_data(self, data, data_label=None, **kwargs):
         """
         Load and parse a data cube with Cubeviz.