FiTech EFI system

I have another question about timing control
Ok when I phased my distributor I set my base timing to 10* and just copied the instructions.
I know my engine like a lot more then that to start and idle good. Should I go back and set my base timing from the very start to 20* and re stab and phase the distributor or can I just change it in the hand held?

Also I noticed there is a "base timing" and "idle timing" does this mean that since I set my base to 10* I can just set the idle to 20*.
Hope this makes sense.
Like I said I was gonna go 20* on the damper from the start but I noticed that most guys where doing the 10*