Ahhh ! I see now. You were taliking about flattening & I was thinking maintenance lappping &/or slurry production.

Think about it. How out of whack should a 8k + stone get with the normal few strokes it is exposed to. That same "new" stone could be shaped like the Sydney harbour bridge & a 1200 plate is then the wrong tool until the end stage of "lapping"

I would think to get an Atoma diamond to lodge in a stone a noob would have used excess pressure & used solely the 1200. I bet that happens a lot hence Stu's advice. It's simpler to have a blanket policy in business to protect yourself.

I would not advise the same for DMT's finer plates as they also don't because the plates are flat & truly the nickel is easily stripped from the matrix unlike the pimpled surface of the Atoma.

btw Stu doesn't make Atoma, a company called Tsuboman makes them Easy mistake reading the context of his reply.