I don't have the benefit of Mr Pipers handbook at my fingertips, however, what I still say is that there is nothing which prohibits carrying out a "power on stall" since this is within the capabilities and certification of a "normal" category aircraft and the Cessna and PA28's are at least "normal" category aircraft. I maintain that it is completely unnecessary to have an aircraft which is certified or loaded for that matter in "utility" category to perform a "power on" stall.