'xxx' I have heard the same saying some years ago & thought good point
I used to fly an old sh*t box 'Sneca' 1 years ago & whilst overhead the city of Melb doing a scenic one of the donks began to backfire so I reduced power so something just above idle & the old girl wouldn't maintain height even well under gross weight. The only difference from that plane to a SE Piper (for Eg) was I had a slower drift down rate,enuf to get back to EN....pheww!!!!
Thread drift I know:-)
I know little of the RAA Reg's but like ALL levels of aviation the rules get stretched!
Wmk2