Are you going to trim it off?
Very nice and healthy! Good Job.
probably not. its not spreading so i dont see the harm
I had a seedling that was slow to grow due to its shoot was all brown kind of looked like your plant's leaf. It wouldn't grow at all, until that is I topped it then it started growing vigorously. I think when you have bad parts of a leaf, the plant still devotes energy to it. When you trim off the bad parts, it reverts that energy back to new growth.