Let's address a couple of things here.

Props: I've been testing many props over the years and one thing I noticed is there is no such thing as the perfect prop for any two setups. What I mean is you can have 2 of the exact same setups in two different areas which might be close to the same altitude, etc. but get two different results. I've tested Mezjlik, Vess, Xoar, Bambula, NX, Belia, ZM, 3W, PT models, TBM and a host of others. The only good way to test is to try others. I've seen planes not like one prop brand and love another. My Ultimate is a good example. It hates the PT models, the Xoar and the Belia, but absolutely loved the Vess. All props were 22X8 and in the Vess case, the 22A. All others would barely hover the thing but I'd get great vertical. The Vess hovered it with ease but I lost a bit of vertical and the plane was definitely louder on ALL of the wood props with the Xoar being the worse. Downline braking on all the wood props, but the Bambula, left me worrying about the speed the plane was gaining on the way down where the CF props had great braking effect and were way more manageable, speed wise.

RPM: Max rpm is NOT what you need, thrust is everything. You can certainly have an engine turning 6500 but putting out more thrust than one turning 7500. Thrust is everything and the best way to get that is to prop the engine so that it is at the top of it's torque band, not rpm range. Most engines stop making torque at about 80% the max rpm. You can actually see this and hear this if you are paying attention.

Just be careful about too much load until the engine is completely broken in