I have done the GitLab OSS program for projects before. They are pretty flexible and there is a human in the loop. This means that you can explain things, such as that seeing as we have a hardware project our license is not OSI approved, but it is OSHWA approved.
The annoying thing is that you have to do the renewal manually each year by emailing a person. However, they are working on automating the renewal process, or at least taking humans out of the loop.
Worth noting that there is an academic program as well as the open source one. Our group use this for both our non-OpenFlexure/GitBuilding projects, but also we do have some private repositories for things like grant writing.