How can I make the trackpad (not mouse) significantly faster? Context

I run a three screen setup and it takes forever to get from side to side when using the trackpad even when set to max in settings. I'm looking for (and thought I had found) a solution that will allow me to set the trackpad tracking speed as arbitrarily high as I want.

What I've Done So Far

I've already tried the solution laid out here. The problem is that no matter how high I set the number when running defaults write -g com.apple.trackpad.scaling x the sensitivity still isn't high enough for me.

At first I thought this might mean that there is another limit imposed besides the one dictated by the GUI. Proceeding on this hypothesis (and the assumption that if Apple throttled the trackpad they would do the same to the mouse) I ran defaults write -g com.apple.mouse.scaling 1000 (note the 'mouse' instead of 'trackpad').

Result: My mouse is now so sensitive that if my cursor happens to land where I intend I can only ascribe it to the will of God.

Remaining Problem

No matter how high I set the number for the trackpad, one motion across its surface isn't enough to get from the left edge of my first monitor to the right edge of my third. Note: The goal here is not to set the trackpad speed and mouse speed separately (as in the question marked as duplicate). I simply wanted to indicate that the analogous steps that work for a mouse do not work for a trackpad. In addition, the selected answer in the duplicate provides a dead link (so not much help). 

The goal is to be able to set the trackpad speed significantly faster than allowed by the GUI in settings. I'm open to downloading a third party tool, but would prefer a command line solution (or explanation as to why the one I've tried doesn't work as expected).

I realize this is probably a pretty niche question, but your help is much appreciated.
You can set higher speeds with BetterTouchTool by enabling Advanced Settings and choosing the General tab of the Trackpad settings.