I don't have the V4 ++ pack, so all this talk about small breasts got me to dust off my magnets and have a go. What I came up with as a first attempt is admittedly not a great morph, but it's free, and perhaps will be useful to someone. I packaged the morph as a delta injection.

To attach the zip, I had to add a ".TXT" file extension. Drop the ".TXT" part when you save it to disk, so it becomes "SmallerBreastsV4.zip". Extract the zip to your Poser folder. The files should end up in:

Runtime/libraries/Pose/DAZ's Victoria 4/Morph Injections/3rd Party

And if you find a better free small breast morph, please let me know.