How about trying just a wedgie instead of the bar shoe? If farrier is also a good blacksmith, he could custom something for you? I had the same problem with one, farrier was good with a forge, fortunately. That worked well with just a rim pad…I hate full pads for numerous reasons including making the total shoe " package " bulky and more likely to take half the effing foot off when shucked, don’t think they solve any problems either. And they don’t stay on if you turnout in anything but a small, bone dry paddock. I’ve watched them run right out of them…and half the foot coming with, of course they’ll step on a nail on the way off and abcess…
The Keratex doesn’t help keep them from catching the back of those dam bar shoes or the cliches hold any better if they do grab one and their feet are even a little damp. Friggen PITA.
However, we did improve things a bit when we added double dose of Farriers Formula or other high quality (meaning pricier) supplement. Go to that, save your money on the other paint on stuff that doesn’t really solve the problem.
Look, he lived and ran successfully without bar shoes, you are never going to work him that often or that hard. He was born that way and don’t think you will do any harm with a more minimalist approach that doesn’t increase the bulk and weight of the shoe “package” to the point it won’t stay on unless you keep him in a padded cell.
Try wedgies and rim pads. And double dose good hoof supplement.