Yes it does sound like it is a wound and not caused from disease.The tell tale sign is if your lips are sticky and sore when you wake in the morning and stuck together. This is because both ulcerated areas are pressed together over night and when you wake you pull the wounds apart opening up them again.
Leaving them alone is a red herring and I'll tell you why, the areas that are scabbing over may not be the areas that are damaged. The reason they may be scabbing is because of damage elsewhere.
MY lip biting was worst just inside the mouth, not the outer part of the lips, but because the ulcerated area could not skin over, the outer skin of the lips had nothing to attach to and so scabbed up. The reason the ulcerated area could not heal is because the mouth closed shut over night and then was damaged in the morning when the mouth opened. No matter how careful I was in the day with them the progress would be reversed when I slept at night because I cannot sleep with my mouth open.
One thing I never properly did on this forum was to investigate DIY mouth devises that stop the mouth from closing overnight, because I feel this would enable the wounds to heal without disturbance and would help a lot of people.