Assigned but unused fields can cause validation errors in VRC Expression menus

[rurre]

Creating a radial puppet menu item, setting the parameter rotation field to something then switching the control type to something else, like a toggle, still keeps parameter rotation assigned. This can cause avatar validation to fail if the now unused parameter is missing. But it's not obvious at all why or where this is happening.

Assigning a sub menu asset then changing the menu item to something else also keeps the reference to the menu, including it in the build, which I think should also be cleared.

To be fair, this is a VRC sdk bug, not a modular avatar bug because the same can happen if you create a regular expression menu by hand, but I think MA could still clear unused fields when building an avatar.