I'm not sure the severely time-limited rush to change the alternator on a single-engine prop before launching it at Ascot was a smart move! Perhaps a rush to fix a racing car is do-able in F1, but surely it has no place in the world of aviation.
An alternator change is a simple affair, a couple of bolts, a couple of leads and then back on, no great sweat and of course the aircraft can still operate on battery for the required safety period if the alternator fails.
It can take longer to get the cowls off and on than to do the alternator change.