One thing @altstore does that should really get you thinking about alternative payment systems that Apple never would have considered: it has Patreon integration, and can tie access to apps to your Patreon pledge — which gives you an entirely different, personal relationship with your users, and lets you use the same reward system you use for videos, blog posts, merch etc. Alternative app stores don’t just have to recreate Apple’s model. And this provides a CTF-friendly avenue (and 1M user cap)