Good idea! I was wondering how I can effectively sand them without wallowing out the hole on the surface sheet.
I had planned to drill all the way and inset tubes. But I kinda liked the look of the countersunk holes in the wood under the drilled surface sheet, so I left them. A sub layer of .06 plastic would've worked better for the countersink, but It's already glued up.
I have some of these bits with my Dremel. I don't want to see any signs of wood grain. I'll try your suggestion. Thanks!