Remember 99% of garages don't have a T4 so think how many operations are done without!!
Now this will shock the motor industry :
The bicycle industry bleed their hydraulic systems from slave end & we've done the same with our electric bicycles !
It works fantastically and much quicker.
If you think about it air bubbles naturally want to rise, so inserting fluid from the lowest point makes perfect sense.
Firstly though give a few pumps in traditional manner to drain the dirty fluid from each slave so as not to be pumping contaminated fluid back up the system into the master.
Works great we've done it on our own cars and have solid pedals.
You have to have 2 syringes, one for inserting fluid at slave and another for extracting fluid at the master so it doesn't overflow.
Enjoy watching the air bubbles end up at top of the master where they should be