Knock learning is not applicable at idle with stock tables on that car.
Log your IAM or DAM as long as its staying around 16 your car is happy in terms of knock. Use learningview.exe to look at the learned timing adjustments and IAM.
I can't comment on your fueling without more data but the knock at idle is most likely not really knock and even if it is its harmless under no load. It could also be purely a mechanical problem, loose knock sensor, loost brackets on motor, power steering pump, failing internals, bearings, etc.
Bottom line is that if your car is not pulling timing much or at all this is not actually a problem.