Those are chrysals, which you are surely familiar with as a self bow guy. They probably won't sand out. Since they are the result of that section of the limb doing more than it's share of the work, sanding them would further weaken the limb and would be detrimental.
I have a short static recurve with the same problem but I continue to shoot it. Suppose it could fail. This bow has continuously dropped in poundage since I acquired it. Might indicate a gradual breaking down of the limbs in that area.