I actually think I'm ok on the adjusters. There's not a lot of gap between my seatback and cage to begin with, but the adjusters are as far towards the cage-side as is reasonable and there's a bit of gap between them and the seatback. My shoulder-harness eyebolts do pull "sideways", but it's not quite at a 90, the plane tilts down in the back slightly. It's all grade-8 stuff though and put together by someone who's built (and seen wreck results from) many cages, I mostly trust the setup
It's cold and dark outside and the car's in the trailer right now, so I wasn't able to get very good pics, but here's a few:
Shoulder eyebolts from the top, with the excess-length rolls moved out of the way so you can see the bolts:
Underside of the same, w/ nut+washer (which I've since painted over - I only masked off the eyebolt top itself when painting):
And this is an example of my lower mounts (they all use the same basic welded-in round plate for the sub straps and belt straps, and the sub straps are down under the seat where they should be - this is one of the belt straps along the wall of the center console):
