I believe that to delete a file from the module library is not the prerogative of the Vassal people, it is the prerogative of those who (supposedly) manage that particular vassal module webpage.
This inability to personally delete obsolete files just leads to server file bloat. Someone pays for the amount of storage disk memory used. Keep that to the minimum - and not have to go through Joel or whomever, to get a or many files deleted.
I think you guys have gone overboard with the retention of obsolete/superseded versions. Every vassal game module and its extensions need only to store/display the current version(s). Anything prior to these version(s) is a waste of storage space. Your server storage space. That has got to cost you something. As time goes on, so does the amount of disk space grows and ipso facto the cost.
While there is always a need for version management and, perhaps, historical retention of previous versions, please remember that the module owners (at least I do) keep most, if not all, of the previous versions. For Vassal to do so is a waste of resources and server capacity. Caveat Venditor applies here. It’s not up to Vassal to ‘police’ what can or cannot be added/removed. Vassal need only confirm validity.
You overly complicate a cloud storage system. Google drive allows you to upload a new version and also delete the old one and also rename the new version. If you want to keep the older version - for version control - then fine. But that is a user/owner responsibility, not anyone else’s.
So. I really believe that you need to rethink the whole system of how vassal modules are stored on your server. The ‘owners manage’ and you provide the storage medium and some control over what can be uploaded. Deletion is never an issue.
PS How much time is spent is micromanaging the way the vassal module website is run?