To Time or not to Time

The thing is, it only takes one or degrees too much timing at any place in the Rpm band, below about 3600 rpm,to cause pinging.
What I mean is, your engine might ping at 14* at 2000rpm, but be fine at 14*@2100 And then want 16* at 2200, I mean it's just an illustration.
So how can you possibly choose 10* at idle and some arbitrary number at some arbitrary higher number? You cannot.
You need to ask your engine every 200 rpm or so " is what I'm giving you too much?" And then respond accordingly with more or less timing and then asking again.
In that way you will accumulate a bunch of data that you can build a graph with, of what is a successful curve. Then you gotta try and hit as many of those points as you can, with never exceeding any.
If that means you have to start at zero advance at idle, well that's just the way it goes. Besides, who cares what your timing is at idle? certainly not your engine. It only needs an accurate curve from stall-speed to about 3600; anything else is a non-issue.