I run a community clay studio, and in this arena kiln wash is a must. The problem is that given the frequency of our firings, our shelves warp quickly. I'd like to flip our shelves every 2 months to combat the warping, but grinding off the kiln wash leaves them with less-than-flat surfaces. So essentially I'd be trading warping issues for surface craters. And if the shelves aren't ground down pre-flip, the kiln wash flakes, glaze drips, etc will fall into the pots below. I'm between a rock and a hard place, and end up dealing with warped shelves until it's bad enough I just need to buy new ones for the studio.
I have a few shelves for my own personal use which I've skipped the kiln wash and have marked the sides A and B with iron oxide wash. I keep a log and alternate which side is fired facing up. When I get my own kiln, this is how I will fire. No kiln wash on the majority of shelves, alternating the sides to prevent wapring. I will keep a couple with wash for glaze tests, etc.
If you know your glazes, keep a log of firing times to predict element health, and are mindful of your relays, my opinion is that it's worth the risks of firing sans wash. And I'd encourage flipping them regularly. Certainly all mishaps can't be avoided, but the more exact your practices can be (and it sounds like you have pretty exact practices) the better risk management you'll have.
Good luck and congrats on the new kiln!