If I were you** I would not discount a young, hungry and professional/interested in continuing education farrier. Find the guy who wants to do better and learn to do better, plus grow his book. Get in on that, understand that it takes time to fix any hoof balance problems and— bottom line— employ the farrier who wants to do the corrective shoeing you need. Either he knows something I don’t** or the guy who fixes all the NPA issues but does that by making a horse wait 9 weeks for a shoeing isn’t trying hard enough to be the technical farrier you want. Amirite?
** Here’s who I am: I have been around and had/seen some very high-end farriery. I am educated in general and in this particularly. I appreciate the value of a good, technical farrier. And I have seen plenty of those guys do fine with the professional- and customer service side of the business. But I am also happy/able to coordinate a farrier and vet (often just with vet providing radiographs and his opinion, but letting the farrier take the lead since hoof balance is within his professional wheelhouse). I’m happy to ask all the questions I need in order to catch up with the professionals and understand all of what we are doing. I attend all the appointments. From this position, I think I’m more or less able to evaluate a young farrier who wants to work with me but doesn’t have quite the résumé as your old grumpy guy. I am telling you all this so as to provide context for my recommendation that you look further afield for someone who can handle your horse’s technical issues without sacrificing all the other stuff.