@lukemperez Thanks! Yes, you should be able to follow people from any other ActivityPub-compatible service, like Mastodon, and reply to their posts. It's documented over at the Help Center.
Sven Dahlstrand
I am an aspiring world's best uncle, co-conspirator with Sanna, and curious coder based in Jönköping, Sweden. If you spot someone hiking deep into the forest of Tiveden, that's probably me. 🌲