Amusing is incorrect, your front derailleur will work ok after adjusting for 2x. To use a 3x shifter on a 2x crank use the middle and outer shifter positions, if you shift into the inner position the cable is slack.

In any case, why bother? You'll spend money on a crankset and have less gear options with a small weight savings. I would leave everything as it is and enjoy the flexibility a triple gives.