On Thu, 12 Sep 2013 11:31:29 -0500, -MIKE-
my cutting will be done with smaller bits. If I have a larger bit to
use, I like to raise it up through the plate, while running, while it
cuts its own hole through the plate.

That's a good point, something you can't/shouldn't do with a metal
place. I never thought of that, guess it's the closed equivalent of
zero clearance insert.