I have no proof…so this is just me assuming…but, my gut feeling is…that for K4 that behavior is ‘by design’. In other words, it’s not going to give you a full working K4 to prevent the use of said characters in…well…you know what.
I’m pretty sure that the transfer is incomplete at least in part because DAZ hasn’t done a Gen4 K4 shape, so GenX lacks something to map to.
Basic Child predates the Gen4 Shapes for Genesis, and isn’t quite a close enough match. Technically, K4 is supposed to be a clone—I guess it’s got all of V4 and M4 in there somewhere to deal with male and female children, or something like that. Unfortunately, whatever it means to be “a clone” of whatever K4 is a clone of, it doesn’t mean that GenX has the information it needs to make things look right.
I tried the full transfer process with some K4 morphs. Transfer all of K4’s morphs as selected morphs without a controller—ALL of them (Select all the sections, right-click, then choose “Transfer:On>All” in GenX). Once that’s complete, open a new scene with a new Genesis figure, transfer a particular K4 shape through the normal process, open another new scene and Genesis figure, and see what happens.
What I noticed was that the body was fairly undifferentiated, which didn’t bother me a huge amount—we’re talking children, after all. What did bother me was that the face was fairly undifferentiated as well. It was a boy, so I tried dialing in M4, just to see what happens. The face gets a lot more definition and differentiation as you dial in the adult morph. Unfortunately, that also makes the body more adult. Without a Gen4 K4 shape, GenX and Genesis itself doesn’t seem to have any idea what to do with the body.
As an aside: one could use K4 itself in “you know what” if one were so inclined. Genesis and GenX haven’t got a thing to do with THAT. The only thing DAZ has done regarding that issue is to make the genitalia unusable with the Basic Child shape.