There is no benefit to using more than 30 degrees...The 28 or 30 degrees that works best for ALL gassers was found by moving the sensor with the engine running.....NO ignition on ANY gasser works best at 40 degrees...Unless you think 25 years experience means nothing.....Experience gained from using ignitions with no electronic control...When we started there was no electronic advance, just fixed timing or mechanical control linked to the throttle shaft...ALL chainsaws and other magneto ignitions fire at 28 or 30...
Too much advance just makes heat and if carried to the extreme will result it the engine cutting out at WOT...Don't believe it ? Try setting the advance by using the point where the ignition actually fires, not some claculated measurement using the width of the sensor holder...
The older 3W and DA ignitions don't use a hall sensor and can't be set by turning the crank slowly to check the spark....The newer 3W ignitions are set by putting the piston at TDC and setting the sensor holder so the edge bisects one of the magnests in the hub...
Which most likely is 28 degrees, not anything near 40....