"The whole point of the system is that the main engines won't be started until warm up / the penultimate minutes before take off."
Interesting thought: Most airlines have the ground engineers monitor engine startup(e.g. if flames are shooting out the back of the engine, they alert the flight crew). Are the engineers expected to chase the airplane to the threshold to monitor startup?
Also, I agree with ChristiaanJ.... For example, if startup fails and the airplane is already in a long queue of aircraft taxying to the runway.... I can see there will be problems getting the aircraft back to the gate if there is nowhere for the aircraft to turn around.
Has this company really thought of
everything?
Sorta reminds me of the in-air wheel spinup devices designed to save wear and tear on tyres on landing (see forum for further info).
Rgds.
NSEU