Can Venus Legacy restore jawline definition in skin tightening mode without fat reduction?

I'm 47 & will be having Venus Legacy under my chin/jawline to restore jawline definition.I have odd bulkiness in the front half of my jawline.I'm very slim so I don't know if it's a fatty layer or sagging but I can pinch A LOT of mass there compared to the rear.I want that bulk reduced, so will Venus Legacy in "fat loss" mode under the jawline actually offer the best definition & tightening results,or is it safest to do "tightening" mode only? I am worried fat loss would cause worse drooping.