[Si Coe]

Lipo's help, but mostly its down to gearing. They only cog badly when overgeared.
Remember, this is a cheap 380 sized rotor in a can finned to make it 540 sized. Although its a 9turn winding, its performance is closer to a conventional sized 10.5T, but with less torque. The result is that its quite easy to overgear it attempting to match the speeds of those with bigger, more powerful motors.

Start with whatever gearing is recommended for a 19turn brushed in your car. And don't forget it is a sensorless system , so will always cog to some extent. However, set up right it should be barely noticable except at crawling speed.