Quote - > Quote - would be very difficult, most of them probably aren't modelled in two or more parts. if you cut the mesh to make them 'zipable' then you change the vertice count and it won't work.

Morphography managed it some how and so has Nerd3D just to name 2.

As your building the dress, you'll need to split the mesh appropriately before rigging so that the vertex count is stable by the time you get to making the morphs.