Oh, about anything not hardy in zone 5, really. Because those I have to grow in containers.
I have only one insight about root pruning. Roots grow because top growth sends out hormonal signals calling for water and nutrients. These hormones cause roots to grow. The bigger the top, the greater the demand for roots. The implication is that a poorly pruned tree, where the top is large relative to the pot, will tend to try to grow more roots, filling up the pot quickly.
So I think we can reduce / delay any need for root pruning by carefully pruning the top to keep it well proportioned to the pot. This is contrary to our instinct, which aspires to a large tree.
It helps to have a big pot. A bigger root ball can support a larger tree without crowding.
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