Ok, in light of the comment on the boards rubbing the rubber membrane off the roof I'm looking at a different solution.
Possibly Yakima Landing Pads:
https://www.amazon.com/gp/product/B0...KIKX0DER&psc=1
I'm thinking I could trim the rubber roof where I mount each of the pads then glue and screw them down. Once dry I can silicone seal around each pad. From there I can mount the landing pads and cross bars. This gets it all off the roof and I think I'll still be below the AC unit when boards are stacked so not changing clearance going down the road.
I guess no ones done anything like this before? I'll be the guinea pig
Thanks again for any suggestions/input.
Randy