congrats, this is an accurate summary.
We will never be able to create awesome, different, diverse, own things if we do not ignore mastodon for the "alpha".
It does not necessary mean that it will not work somehow in the end.

Apart from that the Client-To-Server protocol, Collections and the multilanguage properties …

We are building menschys to make a fully compliant Server and a "reference client", then taxiteam and redaktor as diverse clients … Following you now.

Co-orged the official ActivityPub Confs e.g. in Prague, am elected Social CG Policy Group Lead but if you interested, what Clemens, me and others are building, see the readme chaos :) https://codeberg.org/Menschys/fedi-codebase [we are starting to move to codeberg]