Standalone Minigame in Extensions

As far as I’m aware, Unity engine games can’t be used in Extentions, but if you want to know for sure you should make a quick test app and check for yourself the Twitch iframe even lets it be loaded.

I’m not quite sure what you’re on about here. Any bits transactions in an extension is always 80% to the broadcaster, 20% to the developer, there’s no changing that. Any transactions with real currency are not allowed within extensions.