No nuts, I just use screws wherever. I’m sure eventually it will mess up my table too much, but the spoilboard takes the brunt of it. When it comes to that, I’ll just use the router to surface off the table top and glue a new piece in place. You’re going to have a hard time keeping your machine flat without a sturdy table underneath your mdf. Not sure where you live, but some hardware stores sell slatwall that you could cut to fit your cut area. This would give you basically a row of t-tracks that you could use for hold downs.