My main workbench has a top made of one sheet of 3/4" mdf topped with 1 sheet 3/4" melamine board. It's a good work surface in a number of ways, but not ideal for holdfasts. Between the material being crumbly and the slick surface requiring that the holdfast be perhaps tighter than in some other materials i expect the lifetime of the holes to be short. I drilled it at 7/8" and dropped a holdfast in and it worked, but i can see that the holes will deform pretty rapidly.
Anyone know of a solution here?