Agreed on gloryhole stuff, not for me, but glad you're getting ideas for the future.
As someone who's brainstormed the exact same kind of layered image usage to create a variety of sex scenes - I'd just caution you to not put all the eggs in this basket- because while this method certainly can generate a multitude of scene scene variations, they risk feeling 'flat' or kinda derivative as opposed to hand-made truly unique sex scenes.
I hope that makes sense - again, I know what you're getting at because I've tinkered around with stuff like that myself to a great extent; like standardized dick positions, then changing dick and body below, as well as girl body above etc. It could still be fun, but shouldnt encompass the majority of sexual content for a given update. My 2¢ .