written in help:
IDLE RPM REF
IDLE RPM REF table is used to define idle valve Duty Cycle as a function of engine RPM. Values from the table are executed only when Idle control is not active.
I think it’s a kind of rev pick up when the revs drop. In Case of slow external IDLE valve (not fast as DBW), or very light flywheel - You may need to adjust the transition mode (before idle turn on in work).
RTFM, experiment with settings for accuracy.
im too newbie, and use technique: trial-error-read hpacademy forum and free lessons and so on by loop.
And I was able to set it up IDLE on DBW and very light flywheel.
I spent a lot of time: idle no load, idle with AC on, IDLE when transient pedal, but now I’m very happy how it works.