Questions regarding opentrack (with smoothtrack)

I use smoothtrack (android app) in combination with opentrack and set up the mappings (kind of) to my satisfaction.

What really annoys me is that if I look up, the camera goes all over the place, like down and forward, so I look up from almost the position of the rudder pedals ingame. Looking down and to the sides is mostly fine, but I can hardly use pitch upward without also going to the max of the Y and Z axis. I tried making the curves longer, but I always seem to hit the max on the Y axis before maxing pitch.

My camera is placed below the monitor, could that be a potential problem?

I also fiddled with relative translation, but its effects seem mostly logical. Disabling axes also didn't do the trick and I like that I can move my head around freely and use the emergency sights (when the reflector sight breaks) and stuff.

Also what setting do you use for neck displacement? I have it on -1 because I read somewhere that it's the right position in the game. Setting it positive and higher or disabling it also just seems to make it worse.

Sorry if this post got confusing, I noticed that handling seems best for me with minimal deadzone and mostly linear mappings after that so that looking around stays smooth and there's just a small area where the camera "locks" on the sights when I'm aiming. But I always lose track of planes when looking up (like bumping into the cabin with my head).

Feel free to upload your profile .inis so I can take a look.