E.M. stops with front only and then both 

This is something I like to practice during my slow speed drills and it's one I always practice.
First, I like to use the front brake only and speed up to 20mph for a few runs and then use both front and rear brake.
What I've noticed is there are several feet of difference when using both.
I get a shorter and quicker stop when using just my front brake versus both.
Why would that be?
From what I've read and had explained is the dynamics of how the motorcycle goes forward on the front making a bigger contact patch and the front carries 70% of the stopping power, while the rear will unsettle the front when applied at different times. So, getting them at the same time should be optimal for slowing the bike down, but slowly releasing the rear as the front gets more pressure will level the moto out and stop it quicker, thus the front is the main stopping power.
This is what I've found to work best
I don't have ABS so I have to use what works best and that only comes from practicing the different techniques that I've learned in course work.
In this video, I demonstrate how this works through actually doing it.
Hope this helps and you can practice stopping so you have it engrained in your muscle memory for situations that may arise.
Be vigilant and practice.