Nice set up. My cutting mat is now on a the top of a heavy cardboard that I have on top of a giant dog kennel. I use the kennel for my meddlesome black and tan coonhound when I have to go out.
Years ago when I didn't need a guest bedroom, I built a couple of frames of plywood and furring strips and put them on casters. The inside, open part held transfer file boxes full of fabric. They had 24 boxes in each framework. I did a lot of sewing on clothing then and could spread out long pieces of fabric for cutting.