Hi Rob,
Thank you for your detailed answer. The "access-controlled links" function sounds interesting, but we don't use this scenario at the moment.
We have briefly tested both products, but have also encountered some major problems:
Moodle Core's OneDrive repository allows teachers to link files in Moodle from OneDrive. This is the scenario that is most desired here. Access to the files from Moodle to OneDrive is well regulated: only those people who are also enrolled in the course have access to the files in OneDrive (I don't know how this is managed in the background).
But there is a serious disadvantage: if you embed OneDrive files as a link in Moodle, these files are not updated in Moodle after being changed in OneDrive. There is a tracker entry for this: https://tracker.moodle.org/browse/MDL-72611
When using MS365 repository, files which are embedded in Moodle as a link from OneDrive are also updated when changing them in OneDrive. However, the MS365 repository has another disadvantage: sharing the files works differently. The files are not only visible to the students of the course, but can also be viewed by other students/teachers of the same organisation (if they know the link). This option is not desired by us. You could control access to OneDrive manually, but that is too much effort. However, we still need to look at this in detail to see if the access rights can be managed even better.
We have also had good experience with submitting the requirements for the MS365 plugins directly via Github as an issue (https://github.com/microsoft/o365-moodle/issues). Maybe developments around the MS365 Repository will also be implemented quickly.
Best regards, Anton