budh9534 on AVS had a similar tripod problem. He wanted two legs on one side of the peak to be 32 inches apart to match the rafters, and the other leg would be on the other side of the peak at the middle rafter for 16 inch spacing.
The first tripod he bought didn't match the rafter spacing, but the second one did.
https://www.avsforum.com/forum/25-hd...go-help-2.html
posts 32 and 37
Professional installers tap on the roof and listen for a change in sound at the rafter.
Don't forget the pitch pads for waterproofing.
Please be careful.