How close to edge to mount solar panels

[sonofcy]

I am about to install 4 solar panels. I noticed that the edge of the roof is radiused. By touching it, it seems to be something like aluminium or possibly plastic under the TPO. Obviously the plywood underlayment will not go all the way under there but by pressing down it's easy to find the edge. Can anyone see any problem with fastening the feet through this edge material but a couple inches back from the end of the plywood. Look for the dirt pattern in the pictures to see what I am talking about. The radius is about 4" total from edge to mid point so I was thinking of going in 2 inches from the spot where my finger is beyond my fingertip.
BTW, it is 3/8" ply under there correct?

[JRTJH]

My thoughts, for what they're worth:

Repairing a tear, cut or stripped out screw is much easier on a flat surface than on a curved surface. So I'd move toward the center of the roof, at least enough to allow for cleaning and resealing without increasing the difficulty by piercing the curved roof transition moldings.

As for the roof, most are 1/4 or 5/16" and I'd suppose a few might be 3/8". Typically OSB, not marine ply and even if it's plywood it's probably CDX or BCX, not AB grade plywood.

[sonofcy]

Originally Posted by JRTJH

My thoughts, for what they're worth:

Repairing a tear, cut or stripped out screw is much easier on a flat surface than on a curved surface. So I'd move toward the center of the roof, at least enough to allow for cleaning and resealing without increasing the difficulty by piercing the curved roof transition moldings.

As for the roof, most are 1/4 or 5/16" and I'd suppose a few might be 3/8". Typically OSB, not marine ply and even if it's plywood it's probably CDX or BCX, not AB grade plywood.

I think it's still flat where I plan on drilling but I will put a ruler on it to make sure. I didn't think a 1/4" would be walkable, but perhaps I am mistaken. I just installed a new MaxxFan and didn't think to measure the roof. I did take off the trim ring a couple of days ago but can't see the roof, maybe I will try the other fan that is the original fan.
IF it is only 1/4" I will use well nuts for better grip.
Thanks for the input.