I set my optical centre for 55yds/50m by using adjustable mounts.
Then I lift and turn the turret so it reads near zero for 20-30 yds then lock it back down.
This means I use optical centre for far targets and always dial up for them or ones closer than 20-30.
I normally don't set it to zero, perhaps 1 Moa, just in case I need to change it slightly.
BFTA/NSRA County Coach
CSFTA Chairman/BFTA Rep