Hi,
Its flexible with what I have done now, by default users in edit roles can edit module settings unless they are in a forbidden role that you put in the config setting.
Sorry if its a little work to get your 300 users configured.
I'm not going to work on some complex solution to make it per module at this time, don't have the spare cycles to allocate for it right now.
If you have users that you do want to be able to edit module settings then you would not add them to the blocking role.
Best,
Joe