Cutting to the chase for connecting control resources to target functions can work in two directions. Actions and plugin parameters is all we're after iirc.
You start with the control resources, or you start with the action/parameter.
On the Avid Icon D-Control/Command custom fader maps you can start with the fader. You pick that with the select button, and then TOUCH the parameter it's supposed to control. (see
this little 3 minute video by Brent Heber for details)
In Reaper I'm used to touching the parameter, and then assigning a control resource. I don't really care. I just want to get things setup quickly.
Btw, the GUI for this can be a LUA script. We have lots of talented GUI folks with great libraries.
It would only need to generate a text file after all.