three-eight-hotel wrote:

I know there are some new maneuvers, but those can be learned in the
172 and confirmed in the complex plane as part of the 10 hours.

I suspect that the decision on what aircraft to use for each part of the
exam is at the discretion of the individual examiner. I, too, have been
considering pursuing my commercial but my Bonanza has a newly rebuilt,
turbo-normalized engine in it. As much as I would like to learn and
demonstrate the maneuvers in the Bonanza, I have concerns about damaging
engine heat that might build up while practicing and flying them during the
exam.

A few instructors whom I asked about this did speculate that the examiner,
a certified A&P, would allow demonstrating the commercial maneuvers in a
C172, then demonstrating competency in the complex aircraft (gear, cowl
flaps, and adjustable prop in the Bo).

--
Peter