Gary, I don't think so. As I understand it, Mr Ebihara's technique was the original "screw it to a board" method, and he built wooden grow boxes.Adair, is this. Ebihara's technique? The reason I ask, there is a different root growth response between wide, shallow containers and deep containers.
I offered this method up as an alternative.
My understanding of the Ebihara method is to bury the board under a couple inches of soil. The tile method I posted shows it being much closer to the surface.
Boon gave the tile method out at an Intensive. In fact, I don't recall him ever saying "Tile". I think he was just showing how the roots could be secured down to the surface using wire.
I just noticed today that the trunk wasn't attached by a screw.
The end result, the flat plate nebari, appear to be very similiar. Both methods would have you prune back the heavy roots each year to the point where the new roots will be growing horizontally for a bit before they eventually head down. As soon as the roots reach the edge of the surface, they go straight down. They don't keep going horizontal. So, if you want a really big plate, you need a big board!
I suppose to properly evaluate which method is "superior", someone would have to try both methods, and see which worked better for them.