I don't know if extra oil will help with oil surge on track, but it certainly doesn't hurt it in terms of over filling
I've never even seen a baffled sump for MK5s?! The oil pick up is barely any lower than the balancer/pump assembly, so that bulky piece sat in the oil will help reduce surging on corners.
MK7s have a more open sump as the balance shafts are in the block higher up I believe, so more room for the oil to slosh about into the primary oil separator, which then finds it's way into the upper PCV, and then dumped into the intake