Most simply put: when operating a piece of equipment it's always best to do exactly what the manual says and usually ONLY what the manual says. Don't add steps.
With regard to going to standby, if I were conducting an evaluation or giving a test, I would reduce the evaluee's score for performing extra procedures not in the manual or handbook.
Selecting standby, any time other than when when the unit is malfunctioning or the operator is directed by ATC, would be one such time.