If thrust were the main objective, wouldn't it make more sense to use a milder engine that works better at lower RPM?
Actually, what I like about high revving engines is that you get a lot of flexibility for different applications.
As mentionned, using a very low pitch decent size prop you get really good thrust as thrust is mainly a function of diameter X RPM's. I get above 32 ounces of thrust using an 8 X 3 prop on a glow Enya .09, enough to hover / torque roll / climb straight up on a 28 ounces plane (It revs it 15500 RPM static).
Conversely, if I want speed out of the same engine for another application, I just slap-on or a 7 X 5 (or smaller) and let her rip..
Finally, If I want to slow everything down and get (A little) quieter, I just load it up with a bigger prop.
My other Diesel, a PAW .60 TBR has only one speed: Really slow and quite frankly, a disapointing ability to produce much thrust or speed. I have tried just about every prop under the sun from 11 inches to 15 and about 7 lbs of thrust is the best I ever got. I wish I would have bought a higher revving MVVS .60 Diesel instead, that would have been a much more useful engine for me.