That's a great rundown, and fits well the context of this comm.
I'm glad to see people using RSS again. The protocol has been forgotten by many, but it fills well Reddit's niche as a link aggregator. With a difference - what you see isn't being filtered out by other users, this might be good or bad depending on you.
I do remember people from Mastodon posting in Lemmy, but I can't recall how.
The question will be is the communities heart really in it? Are we willing to walk away from reddit and adopt these other platforms.
I believe that, as long as the contributors move away, the others will follow fashion. The federation has a thousand annoying rough corners, but it'll improve over time, and the underlying idea is rock solid. While Reddit, well...