Ground Balance Question

I might be confused but it seems that the GB does not work like I would think. For example: If I want the 3030 to perform Target Trace when necessary I click the box for Target Trace (this makes sense to me).
If I want the 3030 to perform Ground Balance when necessary (and not have it locked in) I leave the
box unchecked for Ground Balance. Is this correct or do I have it wrong? And if it is correct, does it
seem right?