Hi Tom,
yes, I understand that the terminology seems a bit unclear. Hence my whens and ifs.
You can see the Features for each image, the maximum is very often 40,000, so exactly the Max Features setting. That’s why I think Points is something else. Seems like you suspected to be Tie Points. I just tried something: divide total projections by the number of Points and you will get - tadaaa - average track length. Since we know that track length is the number of projections (as in projected Feature) to one Tie Point, that is the answer.