That’s going to be quite a job even before distribution issue. Jottacloud doesn’t want Duplicati or anything third-party. There’s no documented application program interface. API changes, thus breaks such things.
Jottacloud Error 401 (Unauthorized) is the partial recovery from latest break. Care to be in the next one?
I think macOS expertise is less common around here than Windows or Linux. User base is the smallest.
Duplicati doesn’t provide remote install, so that has to be independently invented. A corporate Windows network could probably do this easily. Do you have any remote access currently to the remote systems?
Is there some other plan for restoring files routinely? Is this maybe just an attempt at disaster protection? Regardless, CLI is less tempting to tamper with, but not inherently immune to what a user might attempt. Running something without a tray icon (e.g. the server alone) can slow them down too, as they’d need to browse manually to Duplicati, and you can slow them down further by putting a password on admin GUI.
Someone may need to do administration somehow. It’s even possible that a repair to backup is needed. That’s lots easier in the GUI, although the CLI can probably do it all, assuming that one can figure it out.
You can’t set 100% identical configurations, all backing up to one folder on top of each other’s backups. They can be similar though, and you can decide how similar depending on how much you trust users to not interfere with each other. An actual malicious user may be the worst, but accidents can happen too.