Well, find a happy medium and leave it be. If that means 1,400 RPM when fully hot instead of 1,200 then no harm.
Every carb'd bike I've ever had has had a bit of a "wandering idle" depending on engine temp. If she runs hard and smooth....that's about as good as you're gonna get on a street bike, IMHO.
Even if you get it perfect......it will change in a few weeks.
~Joe