....Newer pilots ignor it and most systems fly fine ignoring it.
The problem with ignoring it is that you risk setting it up with your servo horn installed on the servo at 90 degrees, when the servo is NOT at it's neutral.
I have even seen them installed such that there was only 10 degrees of throw in one direction with 50 in the other!!!
Yet it will fly OK until you try to yaw in one direction compared to the other or the gyro tries to feed enough rudder in that one direction that may be required to keep the tail from blowing out. There will be far less control one way then the other, Consequently there will be many more times when the heli's tail will blow out when worked hard. That is why you will find some say a certain model of gyro blows out in fast backward flight, while others say it does not, (this will even effect the consistency of the piro rate in certain maneuvers).
So though it may seem to work under less demanding situations, it will not be working near as well as it can if properly set-up mechanically in Yaw-rate mode first for no drift in the hover.