So the ultimate solution to this, I was able to figure out how to assign the volume up key to a custom key combination. I used ctrl-alt-Audio Raise Volume to assign to this key. It will not give you a testing volume to show you how loud it is, but it will raise the volume past 100%. I could not figure out how to bind this to the original audio level up key.

Note I did install xbindkeys before I started, so this may have altered what you are about to see. First add a shortcut with the desired key combo through the original system settings -> keyboard -> shortcuts -> custom menu by clicking the little plus at the bottom. Call this whatever you would like.

After setting this up, open dconf Editor, and navigate to org -> settings-daemon -> plugins -> media-keys -> custom-keybindings -> custom0. For me it was custom0, but choose the index of the key binding you need to alter.

Once inside, you need to change the change the command to a version of pactl set-sink-volume 10 +10% that works for your computer. This is PACTL not PACT(one). The 10 is the device id for your audio system, on my computer it was actually 1. The +10% should raise your volume by that percentage, and take it beyond 100% volume if you have the appropriate sound settings box checked when you run this command.

The best way to accomplish this is to test your command in terminal and then copy paste it later. So copy the command so that the whole line is highlighted as in the image below, and keep that in your clipboard.

After this, you'll need to go back into you dconf Editor window and change the command section of the shortcut for custom0. You need to paste so that when you paste, before hitting enter, there is a special character you can see following the command. Probably a representation of the '

' newline character. Not 100% sure it's necessary, but this is what worked for me.

One of the things you'll also notice here is I bumped the % up to 750%. I found that when it executes as a key binding, it doesn't change the volume nearly as much per keystroke, so I had to adjust this to my liking.

I was also able to recover functionality of my botched default volume key through this menu in dconf Editor as well.

Hope this helps someone out there