I don't tune with the tach --I match props to the task with the tach.
The wierd part is that the shape of the blade has little to do with how hard it pulls.
It is how much it unloads with speed .
Good 3D props are pretty much at upper end of effective rpm power band- on the ground. I get way less than a thou unload on best 3D props and closer to or more than a thou on best IMAC-
Obviously the best IMAC are loading more on the ground- so unload more in the air - it takes a little putzing around but the numbers seem to match which type performance is desired .

tuning -always by ear - the needles - -yep-- just an initial referrence
I am always amazed a guys who get a new engine and it is perfectly set from the factory - (how did they do that?)