Funny, I did almost the exact same thing for a MTG app I’ve been working on, and similarly also started messing with the idea of using the same software to soft launch my own rtcg. I would be very interested to see how you did yours.
Honestly, I would almost rather _not_ share the code, because it's Bad. Like, I just have one big <canvas> element and redraw all the entities (cards, tokens, etc) anytime there's input. It's got terrible performance for being what it is.
I'd kinda rather that no one in their right mind copy what I did.
