Quote - They might well be preassembled in Poser but Vue doesn't always use the Poser shader tree.  (I rarely do - it takes far too much RAM) so I'd still have a fair bit of work to do on them (at least more than sorting out the specularity and occasional reflection map overindulgence)

Not to be snarky, but there's three solutions that pop up instantly: one, supply the old-fashioned single-texture maps as well, just not plugged into the figure by default.  Hell, provide a standard MAT pose for it.

The second?  Well, if you have a texture map, an overlay, and the mask/alpha of the overlay, then you're all set up for Vue, or just about any renderer, as well.  Just do the combination there (or in whatever rendering program) instead of using the Poser shader tree.

Remember, I'm not saying that a complicated shader tree, like, say, the one Bagginbill's VSS creates, or the one that comes with a character like some of Morris's, is part of this.  Only a very basic separation of elements, two texture maps and an alpha mask.  Or more if there are more overlays.

The third?  Tough cookies.  I don't expect shaders from Vue or Max or Cinema4D to be used in Poser (or each other) without adaptation, so why should everything in Poser automatically be set up to do so?