Quote - The young morph seems to inject the young head morph instead of the body.

Just edit the young pz2 to read

{
    version
    {
        number 4.01
    }

    readScript ":Runtime:libraries:!DAZ:Victoria 4:Deltas:Morphs++:InjDeltas.PHMHeadYoung.pz2"
    readScript ":Runtime:libraries:!DAZ:Victoria 4:Deltas:Morphs++:InjDeltas.FBMYoung.pz2"
}

Thanks! That was exactly what I was looking for! Wow, what a massive programming blunder; I'm surprised DAZ hasn't fixed that yet!