They are truly awful.  I can only advise that when you use smiles, you have to adjust mouth height and width, reposition the teeth, and try to take the dips out of the lips because when lips stretch they tend to disappear.  You might have to change the lip depths too.  It seems that Daz doesn't take this stuff into accountability when they make morphs.

However, I've noticed that the Girl 4 morphs work very nicely even on plain ole V4.  You just have to use them sparingly.

There are a million reasons to quit this heartbreaking, frustrating hobby.  This is in the top 100.