Here's my .02 cents...
Let the code remain 1688 by default for LGB's loaded.
+ Add an option on the Rearm/Refuel menu to change the code on any laser guided bombs loaded.
IRL when the pilot pre-flights his aircraft, he confirms the codes are set to specific mission requirements with the ground crew. Heck, when deployed, we usually met the pilot at the jet specifically to set the codes, which they just received in a briefing. It was a few quick twists with a screwdriver, and on to the next.