What effect has the Territory-Based Assignment Selective Update Enabled profile option?

The Territory-Based Assignment Selective Update Enabled (MOO_TBA_SELECTIVE_UPDATE_ENABLED) profile option is used to update the opportunity time stamp during territory-based assignment if the Revenue Owner or Opportunity Owner assignment outcome has changed.

If disabled, this profile option will always update the opportunity time stamp during territory-based assignment. However, to reduce the performance overhead, the last assigned time stamp (date) isn't updated for any incoming territories where the time stamp is the same as already assigned territories.