12:28 PM, Wednesday July 28th 2021
I am currently on this lesson to so take my answer with a pinch of salt.
I would say you have to use your judgement rather than it being subjective. I think most people will find the minor axis to be in pretty much the same place if the ellipse is fairly true.
I would ignore the major axis. Everything I read on this says the major axis irrelevant so I wouldn't use that to gauge anything.
The way I have been doing it is to use the edge of a clear ruler to represent the minor axis and move it until it looks like one half of the ellipse could be folded over on top of the other. I haven't had too many problems doing it this way.