I would think a script to remove all facial morphs from an expression woild be fairly easy to create, but as far as I know it hasn't been done yet. It sure is tedious to uncheck all the non-expression boxes when saving an expression. There are so MANY of them.

It's usually freebies posted by newbies who use expressions like Smile or Pucker as part of a character face, or facial morphs to create an expression, or a mix of both. I think it's because default V4 has a ton of facial morphs and expressions, and it isn't really clear that they shouldn't be used interchangably. Even if they do that part of it right, they often leave the facial morphs checked, so those get zeroed out when applied to a dial-morphed face. As Jafo said, it wouldn't have any effect if the custom face were saved as a new morph rather than a bunch of dial settings.