I think I know the answer to this?
We have unoconv installed and (mostly) working in Moodle 3.1.
In some cases, staff do not want/need this feature and just want to provide feedback and grades. Is there any way (that I've obviously missed) to disable to PDF marking and conversion on an instance by instance basis?
I was going to add an enhancement request in the Tracker, but thought I'd better check first