[otrs] "group ro" and the admin module

Hi all, Do the "group ro" fields in Frontend::Admin::ModuleRegistration work at all? Or Am I missing something? For example, I've set the "group ro" field to "users" in Frontend::Module###AdminUser, and, while setting it so does allow users to see the "Agents" entry, it also allow them to change agents (as if they would have rw access). I couldn't figure out yet how to give them ro access only. Is it possible to only give read-only access to admin modules? Best regards, Cyrille Bollu