RE: "slo-mo training":
Evert MA and even every sport, advocated slow and controlled movements at the beginning stage of learning them.
Its just common sense.
It teaches awareness, proper form, balance and so forth.
BUT the moment an acceptable level of "doing" is reached then "practical" speed is used, virtually always, why?
Because you can NOT move the right way if you do NOT move the right way, in short:
You will never be able to do a move with speed, power and explosiveness unless you DO it that way, regularly.
You will not be able to develop the balance, skill, and your body will not be able to handle the "forces" it will go through when doing it that way.
Psalms 144:1
Praise be my Lord my Rock,
He trains my hands for war, my fingers for battle !