Misury,
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.
I like the waste board that Morgan showed in https://www.onefinitycnc.com/onefinity-projects Ep3. Download the zip file.
You can also see this in the forum at Dovetail Waste Board.
I think that you will find the dovetail spoil board to be more versatile and less expensive in the long run.
Dirkus (Dirk)