Problem on non movable SoB PCB label were now fixed using device attribute.
regarding the solution... (advice from Sjaak)
in the package editor name the label with the same name of the attribute (e.g. PCB_SIZE), make sure its on the top or bottom names.
in the device editor add an attribute to the device and use the same name (PCB_SIZE), add also a default value (e.g. for the a 30x30mm pcb we put DP3030) and that's it.
attribute label can now be smashed and move around.
btw, SoB PCB in dp library is updated with these, so just update you library.