Custom change mermaid wedding dress to sheath

So I really love the top part and the lace of the second dress, but want to change the puffy tulle to a straight sheath like the first one. Both these dresses are from the same designer, and the designer says they can do a custom change to do this. Has anyone done this/ did it turn out good? (I do not want the first dress because it's covered in tacky sequins that's just not for me, and not the lace I'm looking for)