Yeah I didn't see it on the readme either but on forums posts promoting the application (not from developers that I know of). I suppose that misled me.

I am aware they are two different backend but still, I am pretty sure it's possible. Maybe not easy, but I bet it would be possible. For instance, take a look at fedilab. You can see, and interact with mastodon, lemmy, pleroma, friendica and even peertube.