I completely agree this is a good idea, many of us were not initially aware of the fact that power kernel (let alone nokia kernel) would not get reflashed as a result of using backupmenu to restore original state hence resulting in indefinite bootloops.

The idea stated by jOERG is far more easier (in my opinion) to implement compared to making backupmenu somehow flashing whatever the kernel the user has setup the device in. Although by then most users would be stuck high and dry should they see the warning message when hoping to resort to a simple restore operation.