I am currently developing a plugin for max upload limits, this is to limit user groups for membership plans.

If anyone is looking for this plugin feel free to message me.

Update:

Upload limit component complete, has 2 display modules,

this component is made to work with the entire CB_developer package, including CB_groupjive and CB_subs, there is also fields for other plugins that are used to upload material onto the website. ( I currently have projectfork and uddiem also set up for this component) any other components would have to have them set up in the upload limit component,( my developer can do this very easy if you can not)

the component also reduces the HDD space when files are deleted.

each group can have its own upload limit set.

upload limit is set up to use the highest class for HDD space
example:
registered user has 10MB total storage, moderators have 500MB storage, when a registered user get granted moderator that user upload limit changes to the moderator group 500MB storage limit.

when the user tries to upload beyond there upload limit, the users are prompted to upgrade to a package with more HDD space.

Please tell me whether the upload limiter to work correctly if many users use the use the proxy server to access the resource?