+1. My practice is to add conservatism for planned deco dives, but not for dives planned within NDLs.
Mind you, I dive with a D9 and it is plenty conservative enough even on the least conservative setting.
Are you OK reading the D9 U/W? Are all numbers big enough for your eye sight?
I recently started using the D9 and on the first dive with it I was surprised that I had difficulty reading the smallest number on the bottom right side of the D9 wrist display.