So first, lap arks flat with loose Silicone Carbide.

You only need a teaspoon of grit, with a bit of water in a large cookie sheet, to contain the slurry, on flat cement floor, use your body weight and a sharpie to grid mark the stone, pencil washes off on the first lap. It will get it flat in 20-30 mins, it is some work though.
Work your way up in grits up to about 500 grit, then switch to wet and dry paper.

Once flat, polishing goes quickly, or better said, more quickly. Forget the diamond plates, you will just ruin the plates.

You cannot grit rate a hard ark Translucent or Black because the finish is a hazy finish not straight line stria you could compare to. Really shave testing is the only true test.

Prepping with hard steel, burnishing does make the stone perform much differently than not, for razors much finer. A wide chisel or carbon steel cleaver are great for burnishing as there is more to grab on to and add pressure to you strokes. The stone should feel like wet glass when finished.

Quick, they are not, but you should just be finishing on them and 100+ laps are not unusual. I have had some great edges with Japanese Naugras and thin coticule slurry’s. Experiment with slurry.

If it quick-er, you want, add a layer of tape, post 12k finish and do a 10-20 lap micro bevel after making thin slurry with another hard ark.
I have several hard arks, each is a bit different, though I could not say one is finer that another, just different.

An ark edge is unique, keenly biting, but comfortable.