I would just do the bleed. I had a very similar situation with mine. After several thousand miles, the front brake lever throw was significantly longer than the rear. Nice firm lever but just a lot more pull than the rear.

Nothing noteworthy happened that would introduce air into the system. No upside down storage, crashes, etc. I reset the pistons, tried replacing the pads and did everything in disbelieve that air magically appeared in the system. I bled the front brake and the travel is way shorter and now matches the rear.

Bite the bullet...bleed it.