TomD
Given that all Japanese planes with breakers have them adjustable, and apparently they are used to the same settings as here, but those settings are not numerically controlled, I don't see how two out of three of the issues could even be in doubt. Breakers affect plane cutting performance, they are adjusted till they work, though having a number in your head is not relevant in this use. But I don't think I knew any of this solely as a result of Japanese tools. Super surfacers are designed to power up traditional hand woodworking. They did not create the need.