Looking for different ways to hold down spoilboard. In the past, I actually used nylon bolts buried in the first layer that engaged t-nuts in the t-slot frame. It held quite tight, but was problematic in that it was inaccessible.

I did switch to using some screws through angle iron on the side of the t-slot. But I was conservative on the screw depth, as I was worried about deep holddown screws from above striking them randomly, especially as the spoilboard thins out. However, it looks like there's a problem with the screws being *not* deep and numerous enough and pulled out of the MDF.

Any magic answers here I'm missing?