This was always a known risk of having alternative app stores. Think of it from the dev’s point of view, he’s also one of the founders of AltStore. Of course an exclusive app is one of the best ways to get people onboard. Just wait for the Epic, Meta, Amazon… stores next. At least AltStore has an open-source ethos behind it.

I can confirm the extensions work well together.

Have a look at the communities in the instance infosec.pub.