That's funny that you talk about sawing inches off the carrier because that's definitely what they did to my harness. We use the T-bar yahama carries, and a good portion was cut off, so that the snare would fit better. So far, well for three years, I haven't had any back problems at all. I'm not sure how tall he is, but I'm 4'10. I think if he wants to play snare bad enough, he'll learn to carry it. That's what I had to do. Just my two cents.
-Jackie-