Hi Denti,
There were a few pilots who used the same "technique" in the simulator in my outfit. They were reminded about the error of their ways and in some stubborn cases failed and send back for retraining (a failed check will only lead to retraining and recheck, nothing more no matter how long it takes).
Did you really fail some pilots for ensuring they didn't run out of fuel?
Follow the OEM guideline on that and everything will be fine.
Which OEM guidelines are you referring to?
Look at fuel management QRH guidelines "Fuel Leak" ... Leak from engine/pylon confirmed."
After the engine is secured with:
TL ... IDLE
ENG Master (of affected engine)...OFF,
the next line advises:
"FUEL X FEED ... use as required,
If the leak stops, the crossed valve can be opened to rebalance fuel quantity, or to enable use of fuel from both wings."
After an engine is secured and no fuel leak confirmed, why can't you use the fuel from both wings simultaneously in your outfit?