Nav lights arnt just for night use......
Most all other Flight Sims have landing or nav lights (the green and red enabled.)
There are various benefits.
One would be immersion for night oops.
Also if you chose to fly in an arena with limited or no icons, or are participating in a special event that has limeted or no icons its would be beneficial as if you lose sight of you wing man you can ask him to give you a quick flash or blink them on or off real quick.
It would be a nice option to have enabled if it were made available to utilize in the correct scenario or environment. I see several AC skinned with Nav lights and landing light why not make em work.