Installing roof track on LEER camper shell

I am planning to install a pair of frontrunner roof rails on my LEER camper shell. However, the center part of the shell is very thick and I recall most of the camper shell roof is hollow. I am wondering whether I should drill and install the rails on the very edges of the shell or I could drill through the thick part of the shell. Thanks a lot!

 

I did this on my leer topper and went a couple inches in from the curve. I don't think you want to be right on the curve, but close will be stronger than more in the middle.

 

I have the tracks with cross bars I drilled mine closer to the edge figured it was the strongest point since downward pressure will be more on the truck bed than the cap it’s self. Mine come out right on the other side of that center thick piece.