Rockwell JawStand for workshop - usable with a wheelchair?

Has anyone seen or worked with the Rockwell JawStand (http://ift.tt/1DQleY8)I need something I can use while working with tools and I've been looking at the JawStand. For years I had the Black and Decker WorkMate and I never was able to use it. I had the damn thing for 10 years before I threw it out. I just couldn't get the chair close enough. So I am wondering if I would have the same problem with the Rockwell. It has three legs and I thought maybe I could ride over one to get close enough. I also thought about clamping something in and working it from the side.

Any ideas?

Thank you

Rockwell JawStand for workshop - usable with a wheelchair?