I wonder what the engine wear would be after just starting up the engines and immediately applying take off thrust! I would wager that putting full thrust on a cold engine would cause more wear cost than that of burning a ton or two of fuel!
You would need at least 5 minutes 'warm up', also most of the start up snags would then be 'discovered' just prior to take off whilst blocking the line up taxi way!
Quite a difficult task to get the engineers all the way out there.
Great idea, a few hurdles to overcome yet though.