Would be more viable if they had a file upload/download module that didn't allocate a files worth of space per download per user. The FoF module is not usable.
A new version of FoF Upload is being worked on to truncate unused files and map uploads to posts. I think it would be a great addition to add user restrictions too. What an excellent idea, it's the first time I've see someone mention it.
Ref: https://github.com/FriendsOfFlarum/upload/pull/319