I typically leave the paper masking on. If there’s plastic masking, I take that off and replace it with 6" wide low-tack masking tape. Same thing if I end up picking up sheets that have been sitting with my local supplier for too long and the paper is crazy stubborn to get off. In that case I wipe the whole sheet with rubbing alcohol, remove the paper, rinse, dry and then re-mask with the low-tack tape.
I do a lot of projects where I just score the paper so I have accurate placement of other pieces that get layered up. Plus it’s an added bit of protection if I get any solvent drips. So in those cases, the paper is super helpful.
I do a LOT of acrylic (like, a LOT) and most of it is smaller detailed pieces. I end up spending a lot of time pulling masking off with Gorilla tape, so I’m considering maybe starting to run these pieces without masking on the top, but leaving it on the bottom to minimize flashback.