I would however suggest that your advice in this area is not appropriate to some more modern radar units.
I am sure you are right. But not all aircraft are fortunate enough to be so equipped with (for example) the Collins WXR-2100 MultiScan tm Fully Automatic Radar. The original post was intended to be helpful to those who may not have operated such advanced technology. Despite its sophistication, the WXR-2100 operator's guide does however provide useful information to those situations where variable gain is available.