@Darren.Jones Well, this is funny. I would never have expected this to work, but thinking about it, I guess the X-Touch One in MC mode just simulates a full MCU/X-Touch’s behavior to work with the Mackie Control protocol. Searching the forum, I found multiple users struggling with this when writing MIDI Remote scripts.
Is the scribble strip colored? The full X-Touch in MC mode only accepts one joint SysEx message to send colors for all 8 displays, so I assume the X-Touch one “intelligently” maps the one channel to one of 8 “virtual” channels. There’s definitely some hacky magic involved 
How do you assign encoders without the six Encoder Assign buttons? 
More magic! 
Oh, the bundled script, so many lines? 
I guess most lines come from corejs polyfills. The original thing is here.
It works with the X-Touch, but I really can’t explain why it wouldn’t work with the X-Touch one. The relevant code is here.
Assuming that the X-Touch One in MC mode is one very sneaky impostor, I fear there’s not much unneeded code in there, except for some buttons and button bindings 
Maybe you can also enhance the encoder assignments to better suit your needs.
Given you’re not used to JS development, you might need some help with the dev setup. If so, let me know (maybe via PM) and I’m happy to explain some things 
Great news, more than happy to hear that!