Seriously I have never had much long range luck with lowering a horses feet either inside or outside. Reason. You can still win races with a horse hitting it's knees, but you can't win when your horse is dead lame from hitting the ground unevenly. Before you do to much lowering put a wedge in your own shoe, and see how it feels.
Oh my God!! I could not possibly agree with you more!! This has been a major beef of mine forever and a major cause of argument with blacksmiths. Like you said, "long range". The blacksmith looks like a genius right off the bat, but his "contribution" is long forgotten when the lameness shows up.
I actually had a blacksmith one time argue to put a degree pad on the good foot so it would match the club foot. This was after the first argument where I wouldn't let him cut the heel down on the club. The horse had that club foot all his life. Leave it alone.
That's why I like to see how they go naturally and take it from there.
Makes one wonder how many lameness problems started with a bad shoeing job. I would venture to guess in the 90% range.
Astounds me how no one supervises their horse in the shop anymore. Give the blacksmith the stall number and head out.