Lars Grimm
Chumono
IMO, it's best to work on roots and trunk development at the same time. They kind of go hand in hand honestly. They also take the longest to develop so best to get stared asap.
As your trunk grows, you are also developing the root structure. You are also trying to develop nebari, not just getting it into a bonsai pot eventually. If your training pot is too deep, the tree will send roots deep, its what they do. Then you have to mess with them again later. If they get too big before you correct the problems, it can cause other problems or possibly kill the tree.
Ramification and branch development comes after the trunk and roots are developed not during.
A pond basket can be fine for getting very small trees going but not the best for proper nebari development.
I completely agree with this approach. I think the pond baskets work best for early collected or air-layered material to get it really healthy and vigorous.