Hi Matthias,
I'd be really interested in also being part of the development team as we are planning to roll this out at our institution in the very near future but face-face meetings 'might' be an issue for me with work, childcare and other commitments.
Currently I am also a member of the development team and pmc for The Xerte Project (https://github.com/thexerteproject/xerteonlinetoolkits/) and have only had to meet face to face with the team twice in the past 4 1/2 years but we always use github, email,
zoom, trello, etc for communication so for those who cannot physically make meetings it is still very easy to be involved.
We have a forum and community site and transfer issues reported there to Github where we self assign to issues, work on them and commit back into develop.