They might work, not sure. T4 and CVP605 have much in common. I have a 605 but have not tried moving registrations. Just try and see what happens, no harm can be done.
As Toril says you have to be in the correct “mode” to see what is on the usb. If it’s styles you have to be in the styles section, same with voices and registrations. Hit the two registration buttons and the registration screen comes up on the touch screen. Then touch usb on the screen with the usb plugged in and you will see them all appear on the screen. It is something that catches out almost everyone to begin with. For styles and voices you touch the default style or voice showing on the Home Screen and that opens style and voice screens, with the usb/ user choice at the top.
Mike