Here is an option for mounting nuts. These 8020 brand stainless nuts take a bit of filing or belt sanding to shorten and lower the dimple.
They do not drop in or twist in, so I removed the rear corner, looks like a dab of silicone holds it onto the corner to slide a bunch in..
These nuts do not stand above the channel, so bolt right into them, I used 1/4 -20 stainless hex bolts. Theft-proof bolts could be an option.
Fiero Automation put 20 in a mail envelop for me. Probably find them on Amazon also.
