Right now Studio One only allows Precount OR preroll within Metronome setup.
This request asks that we can have both.
If both are selected then the precount will happen followed by the preroll.
When recording musicians, the metronome clicks at the beginning are very good at warning musicians an activity is about to start (so they can stop talking and concentrate), and then they get a bar of music to lead into before punch in. Gives us a nice working pattern when there are a lot of overdubs to do.
That's my use case others may be different.