Come on Dogcharlietree, quote a POH for us.
Not being a smart ar5e - it is an interesting thread and it sounds like you have another angle on it.
POH from Mr Cessna in front of me now states -
CRUISE
"For a given throttle setting with a constant - speed propeller, select the lowest engine speed in the green arc that will give smooth engine operation"
ok for a flat engine, are there other angles?