If I had thought of this, I would have done the same thing. We used a pretty big 12 volt fan sitting in the aft companionway to do the same thing - Funnel air in so it would exit via the portlights. If there was a breeze, we didn't need the fan, since we had the full canvas all around the hardtop, so any breeze that came in through the windshield was automatically forced into the aft cabin and out the portlights. Our 'problem' was getting up in the middle of the night, moving the fan so you could get out to do your business without waking up the other person. Usually, we ended up just doing it in tandem
Those hatches will be a very popular addition I suspect - You may even be able to stand up with your head sticking out while you put your pants on!
Don