I'm diggin' the look of the fins on the verticals. Something kinda' "Trek"ey about them. Certainly didn't hurt the looks any. So I assume the fin maker gave you the measurement to mount them from the rear edge? Is that a constant value or does it depend on the vehicle size, shape, speed etc.?
So, have you taken up the "3D printing" hobby yet? Just thinking out loud here. I really don't know anything about it, but these kind of projects it could be handy to replicate and or modify the design if needed. Anyway, I am looking forward to some data as well. I am starting to become more aware of the parasitic drag we all have introduced to one degree or another while we were busy bolting stuff to the trailer. Unfortunately it seems to be in close proximity to the fin zone. Probably doesn't matter as far as the ability to generate vortices and prevent the low pressure air from attaching the ramp, it's just busy in that region.
Hey, I'm liking the awning cover you got there as well. If I didn't know better I'd think it was a stock item that came with the Aleko RV unit. It has got to be helpful to extending the lifespan of the fabric. Do you transport with it in place or just when parked and retracted? I was able to mount the cover to the awning mounts so it can travel at speed, but that is the type of added drag I was referring to before. I have been tossing around the idea of replicating the design seen at the rear of the Teardrop2, could be tricky but I like the concept.

McDave