Flying restart with sensorless vector control on fan

Lately I had to commision a some drives for fans.
The motors were 22 Kw, the drives Siemens G120.
Flying restart is implemented to avoid trip when starting a turning fan.
My experience is that when the motor is at standstill that the search for flying restart takes up about 2 seconds and the search current has to be setup very precisely : if too high the fan is pulled during the search, if too low the 'speed' is not found and the fan can startup up shortly in the wrong direction.
What is your experience with flying restart on sensorles vector control?

On the drives I'm familiar with (ABB mostly) you simply turn it on or off. The drive is smart enough to figure out how much current is enough and how long it should flow. It certainly is useful, both in sensorless vector and V/Hz mode.