@Miwashi
In opentrack click the hammer beside neuralnet to open it's settings there on the left hand side, below "Camera name" you should see an option for Camera settings. If you open the "Camera Control" tab you should find an option to zoom your camera, adjust focus etc. Generally windows will not remember these settings after a reboot so you'll most like have to adjust each time.
I find I get the best results with neuralnet when I remove colour saturation, bump up contrast a little bit and and adjust the settings for exposure. But I'm only using it for translation so your mileage may vary.
Edit: just as a side note if your camera is a logitech you can probably use G Hub to create a profile for it, that way you just have to start G Hub, it'll load the profile and then you can exit G Hub again so it's not running in the background. It's still a bit clunky, but a bit better than having to adjust sliders every time.