Trackball - Elecom Deft Pro - FN1-3 Programing?

Hello All. This is my 2nd post and please excuse my newbieness but I need some guidance on how to get my FN1-3 Keys programmed and properly set to run on Start up. This is a new piece of gear and I'm not sure which functions I'm going to use yet. Here is the trackball:

The driver that already exists in the distro for the basic functions are working properly for cursor movement and the buttons as such:

  1. Thumb button on left bottom - Left Click
  2. First button to right of medial line above the ball is - Right Click
  3. The Scroll wheel works properly as you would think for page scrolling up and down but is a mystery for [Scroll Wheel Click/Push], I would like it to be [Enter] maybe? (Either way, if you can help me with the options for commands with a link to a map [Fn - Options] for the script I can copy and paste. Frankly, I'm still figuring out what is going to work best with a new piece of gear.)
  4. Lastly, there are FN 1-3 buttons that are programmable.

I really need help with the structure of the script and where to insert it and/or the command for it to run on Start-up?

I've seen the script on Reddit for other Distro and it looks pretty simple but I want to make sure I do it right the first time for this kick ass distro. Here is what I found there but it's specific to the "HUGE" model which is a bit different:

As I mentioned above, I'm waaay rusty on my command line and getting reacquainted with Unix/Linux systems so please if possible give it to me by the numbers. I don't want to go into root and have to wipe reinstall the everything from scratch!

Cheers Folks! Thanks in advance for any help you can provide.