How to prototype floating UI overlays for Android scripting tools?

I’m trying to prototype a mobile app interface with floating overlays — like draggable toolbars or on-screen script buttons — similar to what’s used in tools like arceusX script UI.

In Figma, I can build the static UI, but it’s tricky to visualize how these elements would behave on top of other apps or interact with touch. Has anyone here figured out a smart way to simulate floating layers or translucent overlays in Figma for Android use cases?

Would love to hear how you’ve approached this kind of thing — even hacky workarounds are welcome!