So my truck is a Canadian market vehicle that was later imported back into the US. DRL's are required by law up there. Unlike the US market F150, there is no ability to turn off the DRL's in the little cluster computer.

Well, turns out that there is. I hooked my laptop to the OBD port and fished around in the BCM and found a setting to reenable that menu item. Now I can turn my DRL's off. I've never turned them back on.

 

Voltage isn't set by devices on the circuit, it's regulated to be supplied at a constant value. Although, in this case, the fact that it's not constant is what is causing issues. The higher rated voltage on the 14v bulb just adds a margin of error. Likely the only result is that the 14v bulbs will appear a bit dimmer than the 12v bulbs.