As the Regency era progressed in the 1810’s…

…roundness was now given to the bust by inserting two or more gussets on each side of the hips, and two or more gussets/gores in the bust.  The idea was to create roundness and to lift the breasts.

(Portrait & Extant Stays example 1815: old or young, the objective using hip gussets and bust gores was to lift the breasts and make them round)