Thank you @West, and thanks for all your help, it made all the difference.
And also thanks to @Dwins for the amazingly efficient code that this was built on top of.
Just randomly looked at this project and made a simple enhancement: an ImageCarousel’s touched function now returns true or false if that carousel detected a touch. In the demo this is used to prevent the carousel in the background from responding to touches on carousels in the foreground.