Question is there a way to make only part of a morph work?

[Bastingkr]

i was really wanting to use this morph, but i don't want the change in breast size. is there a plugin that could let me keep the default breast size?

 

[MacGruber]

Obviously you could modify the morph, which is the same as making your own morph.

However, the easier approach might be to just trying to find another morph or number of morphs that reduce the breast size again. Note that there is an option to have morphs go beyond their intended range, including into negative range. There are plenty of breast size morphs that you could try to apply in the negative.