I normally use Quickload to find the powder that gives me the best fill/burn ratio along with the pressure requirements. I have noted, at least in my testing, if I find the pressure value at 8.5" down the barrel at 13.5k psi or higher it will cycle my bolt reliably. This is with a standard power spring, buffer without weights, and a low mass BCG.
I think I will go with the lower velocity test for now and make sure I get good results or at least results that I can work with to improve. Then I will crank it up with full power loads. Some using a little bit faster powders, like Rx7. And another one using a slower powder like Shooter's World Match Rifle. The latter is a ball powder a touch slower than H4895. The SW match rifle load will need to be near full power as it leaves an awfully lot of unburnt powder/carbon residue in the bore when using it for less than 85% full case loads. No dacron fillers for me, until I am out of other options.
Unfortunately, I was not able to stock up on the powders in the 3031/H335/Benchmark/Tac up to H4895 range before the powder hoarding began. I have less than a pound of benchmark left, and maybe 1.5lbs of H4895. I'm going to need to make up probably 1500 of what ever load I end up finding works well. Maybe even more since I will be shooting about 150 rounds a week during the CMP leagues. H4895 is my absolute favorite powder, and I would love to be able to restock that one.