peteroznewman
Subscriber
A kinematic mount does not require that the three points form any kind of specific angle such as 90 degrees. The only requirement is that the three points are not colinear. If you pick any three points near the furthest extent in three directions, could even be directions 120 degrees apart, that is fine.
Were you successful obtaining a skinned surface? That generally consists of more than one face. Please show that.