It depends how the morphs are made or working. A lot of the breast movement in V4 is done with the magnets attached to the figure, in which case applying the magnetise pose should fix your problem. If, on the other hand, the product has added new morphs that aren't in the clothing then you are going to need to transfer the morphs in some way - the latest versions of Poser do have a morph copying feature but for older versions you are, I think, going to need an addon - the V4 module for Wardrobe Wizard, or a XDresser licence for V4, or a set of magnets to mimic the morphs if there is one for example.