Does anyone know what healing looks like for sore hocks?

My senior bun has a bald patch on the bottom of his front paw like a toe pad that’s been red, swollen and inflammed. I’ve been back and forth to the vet the past 2 months with it looking better than worse again.

He just finished 1 week of sulfa antibiotics and 2 weeks ago started taking meloxicam every 12 hours which is now ongoing/as needed.

It used to be very swollen and puffy and an angry red, now it is a lot less swollen but still more red than pink. I have not noticed any open sores this whole time but a white crusting has really developed, there was only a little before and now it’s all over the middle of the bald spot (I would take a picture but it’s an awkward spot and my camera can’t focus on it)

I don’t know if it’s a sign of healing like a callous, or if it’s a pressure ulcer developing with no open wound

Does anyone know what healing looks like? Does more of the white crusting sound like callous or pressure ulcer, if anyone knows the difference?