This is a clever plugin and it gets rid of some tedious work.
My only feedback would be to restructure how selection works internally; right now you’re using physical StringValues that are manually stuck in a folder. This can be automated using a handy function of Enums,
GetEnumValues. This function returns an array containing all EnumItems inside of an Enum. You should use this because, if for some reason Roblox adds/removes Enum values for CollisionFidelity, etc., you should be fine and there would be no work required on your end.
currently returns an array
 = Default,
 = Hull,
 = Box,
 = PreciseConvexDecomposition
You can use
GetEnumItems to retrieve all up-to-date EnumItems for the enums you’re using for selection like CollisionFidelity and RenderFidelity.
I would also use a DockWidget for your UI due to the fact that they can be inset into Studio’s widget UI, but that’s really down to preference.