Fantastic post!

Some small things to note though:

• On Mbin, RSS for users is only for thread posts, not microblog posts.
• Misskey has RSS feeds for external users; source, I use it.
• Apparently the Lemmy engine allows RSS for external sources but from my experience, it depends on the instance to enable it instead of directing to the original feed (might be good to investigate this one).
• From what I was reading in Friendica's docs, if an instance allows, you can turn an user of yours into an RSS-tracking both, similar to RSS Parrot and Saba (the Japanese one).