I’ve had great success with winboat for a lot of software including m365.

From briefly looking over the toot, I think the German version is called openDesk (bad choice as there seems to be some interior design software with the same name) there is a community version you can self host in a docker container. They apparently also have distro packages for Debian and Ubuntu but they seem to have stopped development on those.

Here’s a link: https://opendesk.eu/en/

Would that be a way - have lots of your self created stuff on any device and then sue the corpos or sth for gaining illegal access to copyrighted materials in case they search it?

I wonder how long it’ll take Microsoft to completely ruin their reputation with companies again after they took so long to recover it.