honestly, i don't know if it would help outdoors in most situations. the main benefit of doing this pruning is it creates lots of growth tips all within the same distance of the light, increasing the efficiency of the light a lot. the sun's intensity is almost the same whether 1 foot off the ground or ten feet, so it doesn't do any good if a couple of growth tips are a little closer to the sun.
this method does seem to boost the growth of side branches without regard to how much light they're getting - side branches appear to get more nutrients than they were getting before pruning, so this would apply to outdoors. worth doing one plant to see the effect.