Currently, if I remove the tabletop there is a 2×2′ piece of MDF under it that I was going to screw down to. It is inset, having the legs and sides of the table around it. It looked a bit strange for how nice the rest of the table was. Then I started calculating working areas and realized that if I put a top on the table, it would both look nicer, and increase the build size by 4″ each direction. I didn’t really consider the frame idea.
Now I have this nice top I’ve spent all this time making, but will lose some Z on. Don’t really want to hack a big hole for MDF into it, although that would be for the best, functionally speaking.