The "devices.usb.mouse=0" did not work for me. It disabled my Magic Trackpad entirely. But on the way to trying that, I discovered that my old Kensington USB Trackball (the big one with the cue-ball sized red ball) works just fine.
But the MacBook Pro's built-in trackpad and the bluetooth Magic Trackpad 2 are unusable.
But the MacBook Pro's built-in trackpad and the bluetooth Magic Trackpad 2 are unusable.