The best utility of economy picking here is to make stationary box playing in one position with the left hand sound more like playing laterally with the left hand, and I think is the reason why the elite virtuoso players are so bewildering and you can't tell just from hearing it if they're playing lateral lines or stationary box playing. It's because of the picking technique being used economy picking and because they got their picking skill level so high that everything just sounds fluid regardless of playing in a pentatonic box or laterally