Prevent uneven browning with breadcrumb chicken?
I would try to solve this with a couple of extra flips early on in the cooking process. When perparing similar dishes I put the product in the pan for about 30 seconds, then flip them over and slide them along the surface of the pan to pick up the butter remaining on the pan's surface. It does mean having to flip your meat four times instead of two, but in my experience it works.

It's quite likely that the breadcrumbs on the side you cook first absorb more butter than they strictly need to cook and brown nicely. By distributing your butter more evenly you can get more consistent browning without having to increase the amount of butter used.