I use these on my workshop walls. The slots are not compatible with the typical t-slot clamps used on spoil boards. As far as I know, the slots only support the proprietary hooks and hangers provided by Gladiator, and they don’t make a clamp.
I would still try it out. Shouldn’t be that big of a problem creating those nuts, treading them to smth like 1/4-20
Heck, I would even CNC it from 3mm brass
although it depends how much spacing is there.
I wouldn’t recommend using the GearWall as a spoil board. I have used a similar product as wall racks. The slats I used were made of PVC. PVC, when heated, can emit fumes that are not good to breathe. No matter how careful you are, you will cut into the spoil board. Also, the PVC will become brittle with age.
Another drawback is the price. The GearWall is about $65 for 48" x 24" coverage. 48" x 96" MDF is about $50, which gives you two 48" x 48" spoil boards. An MDF spoil board can be customized to your liking and the way you work.