This was pretty much how I taught my first horse almost everything, and it was very effective. I never used it for picking up his feet, as we started than when he was just a baby, so it was never an issue.
It might be a case of lazyitis (I like that!); that would click right in with his personality, but he acts as though he wants to try, and he knows a treat is forthcoming when he gets it up.
Well, that didn't sound right.
Anyway, he acts as though he wants to, and he does it, but it takes him a minute and he seems uncomfortable. Then I see him buck high, wide and free in the paddock or roll over twelve times in a row, and I think he's putting me on. He is WAY more athletic in that way than was my Arab.
I'll see what the chiropractor says...