Probably totally unrelated but still, it concerns the ear flaps, so here goes:

A couple of months ago, Ellery, my Chinese Crested dog, got encrustations on both ears. Like yours, not in the ear canals but on the tips of his (upright) ears.

I took him to the vet and she said to try Neosporin, that if the crusts were wedge-shaped she would suspect something else but it didn't appear to be so in this case.

I kept the lesions greased up with the Neosporin and they cleared up. They responded almost immediately but it took several days before they were entirely gone.

They haven't come back.