I notice my new cabinet saw and my old unisaw have a two part cabinet. They have a 6" tall plinth on the bottom then a taller cabinet bolted on top of that. Older saw had a cast iron base plinth that may have added rigidity. I do not see the modern plinths adding any stiffness to the cabinet. Why not make the cabinet 6" taller instead?
I do see that on m y delta 12/14 saw the plinth has two factory cutouts to allow dust connections on one side or front/rear. These can be switched around by flipping the plinth upside down
Any reason not to throw out the plinth and make a new one from 8 X 8's to make dust connenction easier.
Bill D