With the correct drill bit for the fastener and the proper installation tool (there's a kit with tool, bit, and a half dozen inserts) I haven't seen the bulging problem too much, but I have before using a drill bit that was "close" and a flat bladed screwdriver instead of the "tool". But again I only did a few, so I can't say these problems wouldn't crop up in time. The others, as mentioned in earlier posts do look like they would work a little better, but then there's the counter bore which if going from the bottom of a stock wasteboard and trying to CNC the holes could be a problem. I think I like plan C, use a material that can be directly tapped. I have a 18"x24" HDPE cutting board that I've threaded and works "OK", but I've been looking at just replacing the whole XXL top with one piece of 1" Starboard, but it's expensive at that size That's why I'm more curious about just making MDF "work". The project the OP did looks pretty good!
I have some time to think about it though as I've recently purchased a new house and it pretty much eats up any "fun" garage time. I've just finished redoing the paint in the garage, waiting on an electrician to set up a dedicated garage circuit, bought an air hose kit for my compressor, started setting up work benches, and bought a mini lathe from Littlemachineshop.com. Oh yea, and I've been helping my wife pick out paint colors, ...meh......
Thanks for the input!