The version of the Modulus UI that we are running does not actually give an administrator access to all modules. However the REST API does, so I have personally been hacking via the REST API when, as an admin, I need to grant someone module ownership: Duplicate reporting module in modulus
I believe that this is fixed in the latest code for Modulus UI, and someone needs to figure out how to deploy this… (I had started here and it looks like Robby configured the database, but I think I dropped this thread.)
Also, we need to continue to look at replacing modulus with a thin wrapper around bintray, as was first being researched in the OWA Store GSOC project (final status update here). Does someone want to own carrying this forward?