Good Evening ,
I use a Callaway x hot driver 10.5,should I set it on open for less loft , if so how should I address the club face to the ball, square ?
set it at 10.5 -square and use it, see where the ball has a tendency to go. Remember if you increase loft it closes the face, decrease loft opens the face, yes its opposite of what most people think. so keep it at 10.5, is you are below 90 mph club head speed put it on 12 deg.
This is a rule of physics and geometry.