The cowl opening doesn't seem to need any reinforcement, but the door does, in particular if cowl pressure is raised with an exit size reduction.
This door has between six and ten plies of 9 oz glass (don't remember exactly) added to the inside of the glass door, and it still bends a little when the exit is closed down; the load is about 10 lbs. An error on my part; this would have been a good application for carbon's stiffness.
Tg for West epoxy may be a factor too, as well as the single latch.