Even in the Airbus with the FMA indicating "Cat 1" you can and may perform a manual Cat II landing.
It was a well discussed subject in my company and finally they said Airbus suggests you shouldn't, but you still may do it.
But you will have to make sure you got the equipment you need, e.g. one radio altimeter, so do so, as that is not ECAM monitored then.
(well on the A320 you'll need the RA anyway as hopefully you won't be attempting an CAT II approach in direct law --- which would still be legal, btw!).