Hi Davey, I see what you are trying to achieve. To answer your first question, in the API, there is a method "ViveSR::anipal::Eye::TrackingImprovements" to modify calibration data; however, I am not sure how helpful it would be. Using raw data gaze data for each eye, one can write a custom calibrator. There is no built-in method to calibrate individual gaze.
Since the default calibration process involves a six-point 2D plane calibration. In my opinion, even if the gaze is misaligned, it would lead to somewhat proper calibration maybe for some population. The user would still see a double image as natural.