It’s a really nice technic to setup buttons inside your Sketch document.
guus dos Santos

Good question. Material Design has shadows for their various states, so I’ve done a little experimenting.

The best solution I have is to create shadow symbols that go under the mask layer in your container symbol. Then you can turn these on it off depending on your state, and don’t have to worry about clipping.

It’s not ideal, so I’ll experiment a bit to see if there are better ways.