The idea of a way to do vertical clamping was one of the things we came across here in the forums before we bought our XCarve, and when we were planning our table, I suggested we go for it. My husband was happy to do it so long as I drew up the plans for it. We did have to alter the arrangement of the 20x20 extrusion to account for the hole (which spans the front of our carve area).
This is the table (we’re still building out our shop, so please don’t judge the dustiness, or the unfinished cabinet carcass that is currently my computer table!):
We have another bit of wasteboard that covers the hole, but we just leave it open most of the time because it’s not hard to reach behind the hole to set up jobs, and we have more than enough space for most of our projects without needing to cover the hole.