Radar in Stby during taxi
Here's my 2 cents worth.
Many years ago in a previous life on fixed wing using older generation radar antennas which relied on physical movement of antenna to scan, it was indeed a requirement to put the Radars in Stby whenever taxiing.
This was to ensure that the antenna was "parked" i.e. held in a fixed position by the gimbal/gyro stabilisation system under power. This did indeed prevent the "bouncing" of the antenna and damage of the very sensitive bearing/gymbal system if not powered up.
With the newer generation of fixed antenna and phased array system of beam scanning, the antenna is generally fixed and the beam is scanned electronically i.e. stuff-all moving parts.
I think you will find this is what is meant when system manufacturers say that "The design" doesn't require power on during ground movement……..
I suspect your earlier AS332's and other helicopters may well have also had ealeir radar's with antennas which physically moved to create the beam scan….hence the teaching of "stby" mode during any movement - in order to reduce potential damage to antenna bearing systems.
As a guideline, I would suggest any radar that has a phased array electronically controlled beam scan would not require power-on/Stby mode selected during aircraft movement. The older generation radars with a physically moving scanning antenna would probably be beneficial to have power applied to stabilise or lock the antenna in a fixed position to avoid potential damage to the antenna bearing/gymbal system….and improve system longevity.
For what its worth……
cheers