Just my two penneth here,
My opinion would be to think about the aircraft you're flying. If the aircraft is going to do something dangerous in a full power stall, then it's probably for the best not to do it, but a thorough brief to the student should be advisable, and plenty of stall/spin prevention training. If it's not particularly dangerous at height, then why not extend the ability of the student? One of the major causes of fatalities is the departure stall, and this is virtually always a full power situation.
To say that the recovery action should be taken at the incipient stage is a little bit strange to me. If the 'incipient stage' is always recognised, why do stalls occur? Please don't lose sight of the fact that not all aircraft buffet significantly prior to the stall, not all aircraft have stall warners, and a stall warner may or may not work when needed. The 'incipient stage' in some aircraft may only manifest itself as a reduction in airspeed, and many aircraft climb very close to the stall itself!