In my experience using an RF-30 style mill, it's a lot of talk that mostly diverts away from getting on with using the mill.
Given that somewhere north of 95 percent of the usual use for one, is cutting to a scribed line, by eyeball, a few simple tricks and some skills development using them, will solve about any of the supposed problems.
Stuff like using a center finder or edge finder, to pick up the edge or a center punch mark. Using a 'sticky pin', nothing fancier than a short pin, stuck on the end of a drill bit with plasticine, and trued up as it spins, to align the center of the drill with the center punch mark as needed.
If you had a mill wired up with a DRO on 3 axiis, I could see the issue, but most people don't and won't put a DRO on one of these like you will with a mill with a decent amount of knee travel.
