I can understand the desire of engineers to do their own ground runs. Having been an avid motor car DIY person I would not like to fix something and then stand aside whilst somebody else proves it. However, running a helicopter is a bit different and the person doing the running would not know the effects of tailwinds over the disc or even understand how to control it should the a droop stop stay out.
As Crab says. A helicopter is virtually flying when the rotors are turning.