For all using the flasher to enable R&D mode; it doesn't work OOTB with BackupMenu installed. When BackupMenu is installed, you cannot enter the update mode, because with an open keyboard BM is loaded. You have to slide to keyboard open just enough to reach the 'u' key, but NOT until it slides into the final position. I've read this here somewhere, and it helped me today.

Btw: i was not able to use the root shell from backup menu, could not logon as root or user because every time BM did something else/ the main menu kept coming back. But enabling USB networking / sshd from within BackupMenu and connecting from an openSuSE box with the quick and dirty / one-time USB settings did the trick.