I've created a piece of open-source software for editing Tone files for certain models of Casio keyboard. It's called "Tone Tyrant for Casio", and the home page for the project is here: https://github.com/michgz/tonetyrant. This is something I've done as a hobby and hopefully it can be helpful to some other Casio musicians.   At the moment the software only supports CT-X3000/X5000 keyboards. However, there's a plan to add additional functionality which has the potential to make it usef