You can only change the parameters that are in the ROV, different firmwares have different parameters and different configurations. If you have more than one ROV it’s even harder to perform this offline configuration.
What you can do is: Download the parameters as file, edit then using a text edit (notepad) and load it back to the ROV.
Thanks for the feedback! As Patrick mentioned, all of the parameters and joystick button functions are actually stored on the ROV so it must be connected to change those. The only thing that is stored on your computer is the calibration of the joystick range. We could potentially enable that offline if that would be helpful.
We’re considering revamping QGC to handle the joysticks a little differently, which would make this possible. That’s still in the early planning phase.