As I understand it, the main fediverse softwares all implement ActivityPub in a little bit different way, and so don’t fully overlap with one another in terms of how well you can see content from one on another and in what ways you can interact with it. Is there a summary anywhere that just has a quick breakdown of what operations (subscribing to follow a Mastadon user from Lemmy, replying to a Lemmy post from Mastadon, etc) actually work or partially work?