Ok here is my exact settings and work flow. Hero 3 black. 2.7 k cine raw white balance protune on of course.
I also use a custom made acrylic ND8 filter I basically found a 77mm plastic (but nice) nd, I then trimmed it down and fit it into the outer rim of a knock off GoPro lens cap.
This was not an easy task to hand trim this thing, at first I thought I would be able to make 3 from one 77mm filter however it would crack and chip so I ended up with only one
It weighs nothing, and zero balance issues on the gimbal.
Once I shoot, I take the card right into GoPro Studio, I remove fisheye and render in the highest quality setting. I then export the rendered file as 2.7k Archive (its pretty large)
then run that through Apple Compressor and put a 2.35 (Panavision) crop on it. Regardless I never see props even before the crop. You can fix that by adjusting the vertical tilt max on the gimbal advanced settings to a less number, and always try to fly backwards to get those sweeping shots. I then output in ProRes 422HQ, and up load to YouTube. thats pretty much it. I do a bit a Color Correction in GoPro Studio, and then check the levels in FCP. I hope that answers some of your questions