@feditips

"...some are very tightly integrated..." [with Fediverse] while "...others are sort of one-directional...".

Exactly.

At this point, I'm not discussing (with, e.g., @matt) the deficiencies (or choices?) of individual pieces of software. I'm looking for info on this for many such pieces.

For me, your already excellent list "What other kinds of servers are on the Fediverse?" would be even more useful with "level of integration" info.

This is a suggestion. Your list, of course.