That is true with any motor! Reducing the timing reduces the performance but also can significantly reduce the heat produced by the motor. In general outrunners are OK up to 20-25 degrees of timing but 15 degrees or 5 degrees will be fine too.
Some 12 months ago Scorpion has changed their recomendation for the timing of their motors from 22.5 to 5 degrees as they have realized that their motors were over rated, or to be more precise the motors were rated based on the neodium magnets with the higher heat resistance they use in comparison to a majority of other motor manufactures, but what good are magnets resistant up to 200 degrees Celsius if the rest of the motor will fall appart at 150 degrees.

Velco