Pant Load, the outright abuse of the MEL and DDG as described previous beggars belief. At the end of the day the certifying engineer hase to stand up also. To knowingly swap a u/s part/component into another system is to potentialy reduce what redundancy was left by compromising it also, just to extend the MEL...... That is a big no no
Grounding a/c usually gets the spares delivered and quick!