I always thought Command ejection meant that if the driver left the aircraft then rear crew had no choice but rear crew could leave the driver to sort things out or make his own departure.
IIRC the Tornado has a selector in the back for front seat/back seat/independent. 20 years ago it was a crew decision which they selected.
Back seat selection does give the option for the pilot to keep trying to save the aircraft and the nav watching the height and punching them out. It also allows for the nav to select it and punch them both out in case of pilot incapacitation.
I was at Buchan when a LU F4 was lost due to pilot incapacitation. Went into a gradual descent and the nav tried to shake him through the gap and shout at him but had to punch out and leave him as they passed 200ft. Command ejection might not have saved him, but it would have given him a chance.