Going back to the two shock cord idea: How about making a removable net from two half circles of netting each with a shock cord across the top. Then sewing on a ridge vent piece of netting about twelve to sixteen inches wide that lays over the shock cords (and your ridge line if you have one). Sew the ridge vent to both side pieces along the short sides of the ridge vent. This will keep the ridge vent piece always laying down over your sides with out any weights or having to flop it over yourself. Like an envelope pillowcase (pictured) You'll be able to enter/exit either side, the vent closes itself, you get a zipperless bugnet with back protection that is removable. Does that make any sense?