When should this feature ideally be used?
when you have SM very close to AP (a few meters, or a few hundred meters). You can see this because signal level it’s too great (-51 dBm or -41 dBm aprox).
Not always is good having such signal levels, because it means the power you receive it’s too big and the AP only looks at you rather tan lookin all SM.
Jerry Richardson has copy/pasted his reply about this numerous times. Which I may add, it a very good one.