Colb, I think you make a good point about thinning being a side effect. perhaps I can create context. Imagine a Freemanni Maple, with one to one stem ratios the whole way. Reducing by some definitions may completely ruin the tree. Doing nothing leaves the tree to choke itself in the long run. A combination of thinning and reduction, or more simply put, 'structural pruning', may be the best mitigative approach. Lightly reducing with 3/4 to 1 inch cuts leaving a 1/2 or 1/4 inch stem, then thinning below that reduction cut. This slowly improves the structure while retaining enough size and fullness. I say 'slowly', because structural improvement in trees with serious issues and/or genetic tendencies is best approached with high frequency pruning cycles. These trees need a high dosage, not with a heavy application weight, but with a frequent, medium application weight.