General

Haven't seen a significant jump in user activity during that period despite the increase in accounts (from ~1.33 to ~1.8k over the open registration period), but can't comment further without additional data points that wouldn't be a good idea to make public (or even collect in some cases).

The number of communities has increased noticeably (98?->116) and there's been a slight increase in weekly active users (125->143) which doesn't quite completely match the increase in account creations.

I don't know whether this is due to people who don't share the values of the instance (enough to fail manual approval) signing up, then abandoning their accounts once they realize the consequences of those values, users signing up and actively using their accounts but not making posts/comments, some actor creating sleeper accounts to use for nefarious purposes at some point in the future, or something else.

Overall this week has been positive but i can't find enough evidence to argue it wouldn't have been without open registrations, and i haven't seen anything that warrants limiting registrations once again.