I needed a 20 degree mount for the iFlight XL frame. While I was at it, I fixed some things that I wished had been on other mounts for the 30 degree mount as well.
On both angles there is NO lens protrusion from the mount. This is due to the ND filter that grips onto the outer part of the GoPro lens. ( yes this does risk lens damage in a bad crash)
Second, I hated having to stretch and push the mount away when tightening the rear screws. To fix this, there are guided hole going right to the top of the mount. This allows you to put your hex-head through the guide and easily tighten your screws without bending the entire mount.
I have printed the example in TPU (obviously) at a layer height of .3
I feel for how we treat these things, .2 layer height just adds unneeded time to prints.
Sain Smart TPU
Print with lens slot at the top.