[rotrex]

Are you sure your reference position for ignition timing is right?
Any modern engine won't take 40 deg timing at anything but low load.
Typical numbers for NA engines past 3000 rpm and WOT are 30 to 34 deg.
Add boost and numbers drop from there.
The methanol I use is fuel for fuel cells and of very high purity. Fuel is from a major oil company (BP), sold in their stations from the pump and should not vary that much. It is used as the standard fuel in the DTM racing series in Germay. I won't test it. Not worth the trouble and the expense. It is not sold in barrels in a shop.

The timing numbers I run are not that uncommon. The methanol water injection allows for an extra 5 deg of timing. Part of this advance is to compensate for the slower burn speed.
A similar engine, but with a turbo without meth water, runs 14 deg of advance at 15 PSI of boost without water.