I would do it a tad differently myself.I have about 25 different powders.I would take a promising powder, start 10% below book max, and load min middle and max load in 1-2gr increments for std calibers like 308. For big calbiers like 300RUM, maybe 2-3gr increments lowering increments closer to max. See how it works for you as far as speed and accuracy goes. I would then try another powder. The powder type is critical. You can't trust the books.

So in other words, if I was going for speed/accuracy with say my 300winmag.And I wanted to do it quickly.I would pick a desired bullet, and load it up with 3 different powders. And out of that, see if anything is promising as far as speed and accuracy. If something looks good, concentrate on that powder, and now fine tune with powder and COL. Only problem is getting close to max pressure. You need to be careful there. As you seem to know.