As shown in the image, how would you prevent xgen from penetrating the hat? I tried it with the modifier "collision" + "hat.abc", but that didn't worked out as we can see.
Is there geometry inside the hat? Just spitballing here, I don't know a lot about xgen, but i had similar problems in marvelous designer before. I ended up making some simple shapes that i drag around as helpers to nudge things into place when needed.