Right @Vertigo1 I've just been outside to double check, with headlights in auto and on obviously as it's dark, if you push the stalk away from you matrix is now in auto, push the stalk away from you again and you have full beam on, push stalk away from you again and you're back to auto. Pulling the stalk towards you flashes full beam.
Thanks for checking but that raises two more questions:
1. How do you turn Matrix/full-beam off again - does a fourth push of the stalk do that?
2. If the above is true then that means there's no way of turning Matrix off without first going through permanent full beam which sounds bonkers.