my two pattern twin boom setups wer swept wing--and I swagged the weight (actually got really close) such that the prop fell spot on the best cg of aprox 27% .
So all the mass was concentrated on the cg and there was NO moment arm on the prop -which I thot could minimize possible flywheel or precession or whatever from the prop.
The use of a good small brushless is a terrific idea for prototyping
for one - the power to weight is truly amazing and no vibration etc., it is truly one of the best experimenter's power plants.
You don't have to build the old conventional structures with a million cut out parts either
use cheap CF booms and basic crutch of foam sheet with the Solarfilm over ribs or formers.
This ain't scale of course -but to prove a setup -it is cheap and dirty and best yet - it works.
I am going to dig out a photo of these turkeys. -