Not really, you just need to have the correct kernel and take a look at the documentation for Flasher3.5. I just bypassed this as I wanted to have a 'race to replacement' for someones new everyday phone after a wrecked USB or SIM error without experimenting the exact way to flash the kernel.
I don't have an extra N900 to experiment with unfortunately or I would document the simpler two step USB kernel flash and then SD card Backupmenu clone procedure.