You're correct that one should observe the aircraft manufacturer recommendations.
Of course, I'm correct...use of ice vanes (inertial separators) is nonsense, unless the runway surface is contaminated....gravel, dirt, loose snow, etc....especially, when maximum performance is necessary off of shorter runways and/or obstacles.
Positively confirmed via discussions recently with a senior FAA ops inspector.
And yes, it ain't changed in many years.