Will a 2 inch Latex Topper Firm up a mattress?

Many users have claimed the benefit from addition of a 2 inch latex topper to a mattress. Topper provides good support and reduces the pressure points while sleeping.  However, it will not firm up a soft or sagging mattress, even with addition of an Extra Firm Latex topper. This is because a topper needs a firm and uniform base to function properly. It will not be able to cover up sag or a dent in a mattress.  Solution to this problem is to first firm up mattress before adding a topper. A 3 inch topper performs better, but will not solve problem associated with soft or saggy base.  One of my associate had this problem and purchased a low cost firm spring mattress to get best of sleeping combo. The spring mattress provided the flat firm base while the latex topper provided comfort and pressure point relief.