God, the glitch pulse physics. SEND HELP
Ok so, here's some help I guess.
It pushes you back depending on your current speed when using it. The faster you are at the moment of hitting the key, the more it will push you.
If you hold it down, it will continue pushing you until you release it. So if you want a smaller push back from it, just don't move around when using it and give it a little tap.
If you want to be pushed further, move in the opposite direction first, then use the glitch pulse and hold it.
Hope that helps!