So, on my drive back home (Oakland, CA to Orlando), it rained a few times.
I noticed some dancing water and had my camera handy to take a quick shot of it. That big blob of water was spinning and occasionally it would shed a drop.
I'm thinking, as a simple modification, that a small fin attached just behind the mirror support would resolve that - and perhaps knock down a little noise. Frankly, I don't think I'd see an appreciable FE gain - but I don't expect any one change to do that Any other suggestions?
Time is the best teacher. Unfortunately it kills all its students.