Not sure whether you're more interested in ventilation or privacy.
may not suit your use, but to have both shade and port opening, I have seen exterior scoops made. The ones I saw had a forward rectangular "mouth", shaped from small diameter rod, the sunbrella slid over that, and then was snapped above and below, and aft. I believe they were home made, but not a difficult project
. The virtue, of course, is that they are little wind
People work out solutions, for privacy, including curtains, which can be slid back and secured or pulled closed and secured (snaps or velcro). Thin white cutting board material makes a translucent shade for keeping out bright sunshine, and will stay in place when opened if cut carefully enough to a tight fit (all that holds it is friction on the hinges and knobs), providing privacy, but not air scooping.