I'd keep MDM on at a minimum until you learn how to properly react and correct a potential spin. I had a friend who knew in theory how to correct a spin, and did a few track days with DSC off with no problems. Then one day it happened and he just wasn't fast enough and spun into a wall.
It's pretty much a fact that once you drive with DSC off and start pushing to go faster, the rear will come out more often and you need to be ready for that situation.
(1:40 @ Laguna Seca, 2:09 @ Thunderhill, 1:56 @ Infineon)