Tricks to use bottom threads of cap nuts?

Installed my tracks on my campershell yesterday. It got me thinking. Once the cap nuts are tightened on, there is some thread that I can see. There is a small amount of space around the threads. Too small to get a normal but in there but I’m wondering if there is any way I could use that surface area to organize/utilize the ceiling area of the shell. I’m hesitant to put anything between the cap nut and the surface of the canopy so I’m hoping there are some clever hacks people have figured out. Any ideas? Thanks!

 

The cap nuts are rounded to help preserve the skin on your head. Most folks seem to end up using some variation of the D ring picture hangers under the nuts. As long as you use the larger size and get them flat against the shell they just work like a large washer, no issues.