Attic hatch is a piece of drywall that has a piece of batt insulation that I have to try to pull over top as I close it.
Can I glue a bunch of rigid insulation to the drywall like the picture below? Or will I need to cut a new chunk of plywood?
I don't see why you could't attach to the existing. I would try to find as thick a piece of ISO as you can to eliminate glue joints.
Why not just the bat to the drywall??