Starting from impact bag makes so much sense.

Interesting your jazz influence (drums). I used to teach Harvey Mason while I was a lead instructor at CompuSport. but he was more than a student, but a friend. Saw some great Fourplay concerts back in the day.

Shaft perpendicular to the spine is music to my ears. Went round and round with Martin Ayers on that subject (who is steep coming down and flattens late which raises the handle during impact via a force on the shaft based on where the club head is at the top, not laid off after transition).