Don't know if this is any use to you, but thought about the overlap for netting on a 2-piece A-frame door being secured by light shock cord loops sewn to the corners of the netting and attached to buttons sewn to the outer bathtub wall of the floor. The thought was that you could easily reach into the overlap, down to the button, and remove the loop to open. Vice-versa to close. Thought about doing this also for emergency A-frame doors made of light cuben to be unrolled when the weather got really nasty - upside down rain, and all that.
Like you, found the #3 zippers too handy and used them for the net doors. It may be partly psychological - keeping out creepy crawlies, and all that.