Not helpful for the original question but I think a craftsman repairing cracked glazing would have to remove it either with a solvent or careful abrasion, or both, and then re-glaze it and polish the edges. Long, long ago I crafted leather bags and sold them to specialty shops. We stained the edges and used a product called Edgecote to seal them and then a polisher to give the edges that completed look. I used my own bags and don’t recall a problem with the glazing cracking so this era of cracked glazing has perplexed me, honestly. Glazing will wear down, just like the rest of the bag will, but the products now used to glaze edges may be heavier and more prone to actually cracking. Just a guess.