In my opinion, ALL nessaging apps should be compatible with each other. It should be like email, just different clients on the same protocol. I know it won't happen anytime soon (if ever in my life), but I'd like that. And we should start somewhere. Maybe here.
Where are or were those checks exactly in the Lemmy software code? Yeah.
If they were on the lemmy.mlinstance, it's in their right to do so. It's their instance. The basic codebase, which other instances are using, has nothing to do with it.
It's the idea