@gamehawk about 300 active people and 680 users, but I see a lot of traffic from them on the timelines..
social.tchncs.de and chaos.social are reasonably large and well run, but (unsurprisingly) much (but not all) of the local timeline will be in German..
@gamehawk cybre.space has been around a while and is popular/active (I have an alt on there and should be able to send you an invite) - they do use a forked version of the software with a single timeline (this may or may not be an issue)
@gamehawk it looks like this. There is only one timeline rather than the 3 you get on normal Mastodon (if you click on the links at the RHS the middle timeline is replaced with local or federated or your notifications...
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