Here is another method using the counter canter
As to the question. Yes, first I two track them both directions at the walk and trot.
When they are good at this, I will move tot he canter, two tracking in both directions, first into the lead I'm on, then in opposite direction, without letting the horse break. He has to change
Basically, lead changes rely on that hip control and keeping the body straight
I used to do western riidng, which requires a horse to do a series of flying lead changes at precise markers, without speeding up or loosing cadence