Pity
Agile hasn't bothered to read Safety Notice 37 Frank has taken the bother to include at the back of the POH.
let the RRPM decay to about 40% and go to max manifold pressure while keeping the same RRPM
Ever heard of detonation
Agile? That's exactly the territory in which you have the engine operating, high boost low RPM. Heaven help any pilot, or passenger, that flies in an aircraft after you've had your hands on it. I'm surprised it would fly with the engine producing so little horsepower, it's off the Lycoming manufacturers 540 chart so can't be estimated.
how would Captain Agile know the RRPM was at 40%?
Pertinent question, not familiar with Robinsons but see the tacho bottoms out at 46% in the photo I looked at.