puppeteer, I do know multiple ways of animating a button (though yours was one that I didn't know of yet and sounds very interesting). Problem is that all my buttons are created at runtime and dynamically, so it would be more work than we'd get out of it. Of course it can be done, but without a "animated-button" element in A7 I won't bother, it's not worth the trouble since we haven't even made the bmaps yet.

Also, I can't see how to highlight a button without more additional code when hovering over it with the mouse, using your method. I may rather update the button using pan_setbmap in a loop.
That being said, I'll keep your method in mind if I run across a situation where I really need an animated button, thanks!