I agree once you get up to motors in the range of 50-60mm dia its ok to set up more pitch and slower RPM. Ive run a 5330/24 on a couple of planes and it works fine but you still mind the loads and test props. It could turn a 24in prop at 48A on 10S but that was years ago on earlier battery tech. Today with decent LiPos Im sure it would do even better.
I thought the DLE data you posted was ground tested I thought no way Im getting those figures! I just dont see the DLE 35RA really making good use from much more than the 18X10 at this point. Its like the 55RA I have I tried different props and like you I tried a 22x6/10 and the result was poor on a TF Corsair. It just screamed and went nowhere. I landed almost immediately and changed back to 22x10. The blended pitch lets the engine turn high revs but its not pulling as hard.
Point of fact about electrics is that there are no IC engines that can produce more HP than even a conservative out runner motor set up in each engine class. Brushless systems out perform gas and nitro engines in just about every application except turbines. Even then EDF set ups can out perform the smaller turbines until about 90-100mm and then turbines take over due to cost, performance and reliability. Plus a jet engine is a jet engine, you fire one up and everyone knows whats under the hood, the cool factor is 10! Thats why I prefer turbines but thats another story.