I tried that as well, however it was still not quite the right tilt. I think you're right it's just the session case. For future reference, for others here - I used and m5 for the gopro bolt and nut. The m5 nut was superglued to the mount. (Gopro uses M5 normally as well, so it's gopro screw compatible as well). Thanks for posting this @bud_hammerton
, I love it. Just got my first footage on it today.