Didn't say it was broken, but following the sequence through several different individual's methods I come up with some confusion. Coating before applying checks makes it difficult to apply checks to now oversized shank. Reason for not applying check first is perceived need for lube and subsequent lube removal (or) sizing before coating makes slick bands and powder may not coat as well. Hmmm.
I have none of these problems, actual or perceived because I apply checks before coating, lightly pre-size without any lube (either just to crimp the check securely as Max mentioned or with a tighter die to reduce the whole bearing surface diameter slightly depending on cast size vs desired final size), and shake the bejeebers out of them with the BBs to ablate the oxides off the bullet surface and get a really nice embedded coat of paint on them. I.e. it makes me feel better and I know the substrate is roughened and oxides blasted off by the aggressive shaking action and the abrasive powder, and the bullets are otherwise unharmed.
That said, the gas checks are pretty slick and the powder adheres to them extremely well. Also, powder that is ES sprayed onto bullets that have been pre-sized adheres extremely well, so really it is only a matter of preference what we do; the stuff will stick.
I thought that dry-sizing checked bullets would wear out a sizing die, and eventually it might, but several thousand bullets through my .309" and .451" Lee dies haven't changed the dimensions yet, so I'm not worried about it.