You have a point there...
Though I would say the abuse is locking the reference thread for the flag. He cannot add a self-mod thread as reference but instead opens a normal thread and locks it.

I propose that flag reference threads can be locked only by mods and preferably only in certain situations like when OP removed support and issue solved and there is no more useful info just spam... perhaps then. Just an idea.

To revoke forum features for some particular users might not be the right call.