I can't swear to this, yet, but it seems to me that if you prune when dormant, often only the apical bud will break dormancy. If you let them break dormancy, and grow a little bit, and then prune, they will flush multiple buds. So, I would expect tat if you pruned it to the point at which you want branching (if it is still actively growing), that the same flushing of multiple buds would probably happen.