Turns out, it's still way too quiet over there. At least my bubble seems to have quieted down massively again. A few selected groups seem to have made a home and built out their circles, but from what I can hear, it's mostly crickets in the night.
And, the API itself and some of the tech design around it reminds me of the same trouble Twitter went through at the very beginning. One major instance had to kill all their keys a while back (if I remember correctly), so over night, all my users were deauthenticated. The rate limits are quite tough and all designed for one specific use case, and unusable for another, etc. etc.
And every single instance could be sticking to the recommended configuration and performance considerations, or not — it really depends on the person who runs it.