yea, I'm unsure what it is. Possible side effect? I just found it odd that when I went to replicate what I did on the other build, I couldn't with these.
But again, just throwing it out there as informational.
I am only able to use that 1280x 3:1 aspect at 21fps stable with no skips with this build, I will try Fix2 just to see what happens, you have me curious.

Update: well still no 24fps but I am able to get 22fps with those settings with Fix2 so must be a bit better, but the only addition is Fileman so I can try this new build without fileman and see what happens.
Update2: No, fileman does not make a differ, results are totally random at 22fps for me sometimes it never stops till I stop it, sometimes I only get 66frames.
21fps works perfect either way at that res.
Tragic lantern version has a cool greyscale preview option while recording raw, it shows exactly what your recording, much nicer to see what is being cropped.