We are still in what I consider a testing and fixing stage, as there are some known issues, which we need to either get working (and they may fix themself) by having more people testing, or get some better feedback through #AskMastodon about what might need to be done.
The instance is at https://mastodon.openpsychology.net/ and anyone is welcome to join, especially if you feel up to providing feedback. And please feel free to boost. The admin is @lead which is also myself.