Hello. I just signed in as one of my designers and they can set the status to 100% without any other access needed. They need to be assigned to the task though. I hope that helps.

I think it would also be helpful to be able to check-out PROOFS (currently you can only check out a document). We have a problem that the designers like to upload a new proof or resolve comments while it is still being reviewed... and sometimes comments are steted.