I strongly doubt you would have any trouble on 12S IF you limit the power to the listed maximum of 3kW. This has been hotly debated with several other motors, but the break-down voltage of the winding insulation is much higher than this. The bearings will not be likely to be on their speed limit at 11S - there is normally quite a lot of excess capacity in the bearings. Going up in voltage and down in current (using a smaller pinion) will make the motor happier, with less resistance losses to heat. Motors are power limited, not voltage limited. If you don't agree, you are welcome to your opinion too, but don't feel the need to flame me.
the breakdown voltage isn't what limits the motor. in fact there is no hard limit on what a motor can or cant handle other than the thermal limit.
e.g. you can run the motor at higher than spec volts, at the expense of bearing life and efficiency (due to friction and fanning losses).
be sure not to mesh too tightly if using higher rpm, as the extra load on the motor bearing from a tight mesh will not help with longevity.
as for the less resistance loss, thats true. whether it translates to a practical increase in efficiency, and whether the reduced reliability is worthwhile, is up to the user to decide.
RIGHT on, Kim! Good to see someone who has a clue about electric motors on here.
EXCELLENT MOTOR! I use it in my HK-600GT heli, with YEP 120A ESC (HK's smallest HV ESC in that range), 8S 3700mAh Lipo and 14 tooth pinion. Max performance 2250W at 80A. Motor comes down warm and unstressed. This motor fits the HK-600 frames WITHOUT MODS - nice! Stall-turns are up to 500 ft high, showing incredible power. So much better than my T-Rex 450, and it's using a Scorpion motor!