There is not much point in reversing the boot order. If you boot into the Apple firmware it doesn't turn off but only enters a sleep mode. This means that you have to reset the Ipod to reboot into Rockbox. And when resetting the Ipod it doesn't make much difference in which case you flip the hold switch -- if you had booted Rockbox before and don't do anything you stay using Rockbox, and if you used the Apple firmware you stay in the Apple firmware until the next forced reset.