So, little known secret that you can try: sesame seed oil. Yup, the food-grade kind like Dynasty works fine. Sesame seed oil contains the same proteins in it that are in skin cells, so it works to heal burns and multi-layered skin problems. Works sunburns - I mix it with sunscreen so that the sunscreen goes on easier. I haven't tried this on my horse, but I absolutely woud if it were applicable to something she had going wrong. It has a pleasant, nutty smell.
What you need to do is get the skin remoisturized and allow the cells to heal. Any oil or ointment you use should be warming (coconut oil is cooling, sesame is warming) - massage it in well (massaging the skin can stimulate cell growth), and then you can place a mild-adhesive bandaid over that area to trap in the moisture and allow the skin to absorb and metabolize whatever you used. Use water or oil to loosen the bandaid when it's time to come off - then it'll slide off instead of take hair with it. Eventually, the scab should simply pop off of that area, and new skin can grow and heal.
Corona ointment or Neosporin (meant for keeping wounds hydrated and disinfected) might help, and ... I have another, but I have to run out to my barn and see what it is. Haven't had to use it in a while, but it's guaranteed to help hair regrow...even under scabs and abrasions. I never had any reason to believe it didn't do that.
No diet, no hoof. No hoof, no horse. No horse is not an option!