So, already found an issue when just trying to start this mod. As soon as I press the keybind to open the new GUI, the game instantly crashes.
This is true for any key that I rebind it to and is reproducable every time.
There are no incompatabilities that are causing this as I am only working with Music Trigger and the Impossible Library just to get a feel for it.

Here's the crash log I got from this:
crash-2023-01-05_11.24.12-client.txt

Noted

Looks like this crash only happens when the main config file for a channel is empty which is basically what you already figured out. It will be fixed for the release

Fix already found: Mod does not function with music turned off.

This has been fixed in 6.0