I really really would not worry about "transfer their Kontakt Libraries" - all of us who build pro libraries would gladly trade a little rework on an existing product for more usable space in the interface. Of course there has to be some limit to how big a VST interface should be, and setting the width to some silly big number seems, well, silly. But in the end if you just set the vertical limit to (say) 650 and allow that to be the dimension that can be programatically changed then setting the width to the kontkat 633 should be fine…
C