I was working with a customer in Indianapolis who had a huge DriveWorksXpress implementation. The problem he was having was that DriveWorksXpress could not switch to derived configurations of his sub-assemblies. [It wouldn’t drive dimensions either.]
Turns out since he was working with rather large assemblies, most of his parts were lightweight. DriveWorksXpress cannot modify parts that are lightweight. Thus, you need to resolve all of your parts before you run a specification with DriveWorksXpress.
You won’t find this in any help file, but who needs a help file when your old buddy Jeff has your back?