Currently, with our multi-Element editing featureset. we offer the user the ability to, on multiple Elements at once:
1) Change the Property Value on all selected Elements
2) Clear the Property Value on all selected Elements
3) Create Bindings/MultiBindings on all selected Elements.
4) Apply Resources to all Selected Elements

However, there is one item in the Property's 3-Dot menu which does not function and apply to all selected Elements; the 'Create Keyframe' function.

Repro Steps:

1) Download and open the attached Studio Project.

2) In the Navigator, identify the UserControl named "TopographicPattern_UserControl" (found under the "Foreground_Group_Grid" Grid under the RootGrid.

3) Enter the TopographicPattern_UserControl's context menu, and open the UserControl's Template for Edit
This will then open in the dummy Template Editor.

4) Within the UserControl Template, navigate to the Animation/Storyboards Panel, and select the Storyboard named "TopoPattern_Animation".
This will open the Timeline, where you will see 60 Paths with their Opacity values keyed.

5) In the Navigator, find the Grid named "TopoPattern_Animated_Grid", and select all of the Paths contained within by clicking Path0, holding 'shift', then clicking Path59.

6) With all 60 Paths selected, and with their Properties Panel exposed, on the Timeline, move the playhead to the 8s mark, and click the 3-Dot Menu on any of the path's Properties ('Fill' is a good candidate, as it has a value already).

7) Within the 3-Dot menu, select 'Create keyframe'.

Observe how only the last-selected Path has a Keyframe created for it.

8) Attempt the same operation, but using any of the other 3-Dot Menu actions.

Observe how all other 3-Dot actions create Keyframes for all selected Elements.

Expected Results: the 'Create Keyframe' action functions across all Element of a multi-selection, OR, if 'Create Keyframe' can't be used in a multi-selection, then the option is greyed out until only one Element is selected.