Seriously?
" it's either disable the vehicle for a refund – or don't, honestly."
I clicked that link out of curiosity..... Are they serious?
Why do I suddenly detect a load of RPi's and/or Arduinos and some big MOSFETS becoming popular....
And if you did return the controller for a refund, what the heck are you supposed to do with and dispose of the rest of the bike and it's battery?