Don't do it with 1+0.
There is a reason the preliminary cockpit preparation has a safety check that the flap lever matches actual position.
It's not about the warning, but rather about someone making a safety assessment and formal fault tree and seeing the fruit at the branches' end.
It's about not being smarter than the manufacturer. They spell SLATS which may suggest 1+0 and my experience is that you shouldn't.
F/CTL
FLAPS....................................................... .............................CHECK POSITION
Check the upper ECAM display to confirm that the FLAPS position agrees with the handle position.