Red ball clay? That’s akadama.
One has to get the tree really energy rich for that type of cut back.
The master also says you can grow them out in pots and boxes btw.
Cheers
DSD sends
They say 'akatsuchi' so not akadama. So red soil and black soil.
You can leave leaves on the branches while still reduce the number of shoots just before the growing season starts.
Then remove the flower buds manually, keeping the leaves around it.
I believe he just chops everything off at many parts because it's convenient. But I also wonder if they do any cleanup of new growth when shoots start to backbud.
You may get a ton of buds. But he explains that 'fewer buds is better, and let them elongate as much as possible'.
Never heard of 'soft trunks', You mean the bark is softer when field-grown compared to potgrown? I also have never read Watanabe's book.
Anyway, I don't believe in using cut paste. There is no reason to use it because of Shigo's work on plant wound healing & CODIT.