Checked my cam advance switching points.
It does not seem to very losd related as it happens at the same rpm under gantle driving and hard acceleration.
Advance activated at ~1750 rpm.
De-activated at ~ 1250 rpm.
Remains activated up to >5000rpm.
Curent ~1.0 amp during activation.
It seems as if this is OK as it agrees with the values in MB doc 05-2160.