[risner]

To be clear:
Say I created this object:

In-Play selector widget (adds a line in In-Play tab that initially is set to "None")
When set to None, doesn't do anything. If None needs to be a template called "None" that is ok too.

Add two templates:
Wild Shape Polar Bear
Wild Shape Treant

These templates have tags "WildShapeForm" that the widget uses to know which Templates are allowed (so it doesn't show all templates.)

When you go back to In-Play and click the selector on the widget, it now says:
None
Polar Beat
Treant

If you remove the Treant template, it is removed from the Widget's list.
If you add Wild Shape Monkey, it is added to the options in the Widget's list.