@johan
Can you elaborate? Why do you expect ‘most devices’ will?
Are you referring to commercial devices here (not custom builds)?
This presumably is not standard automatic behavior built-in into most of the common LoRaWAN stacks, but is somethings that will have to be programmed into the application logic explicitly.
Is the documentation for doing a ‘migration with preservation of security sessions’ already available somewhere? If not, when can it be expected?