I used to work part time for a brug hybridizer. When plants got very root bound she had me root prune them before jumping into larger pot. She would say "abuse them Ginger...they will love it" Don't know if that is true for hibiscus, but she grew great brugs.
Each cloud has a silver lineing if only you look for it.
Don't know if that is true for hibiscus, but she grew great brugs. 
