Do they take up too much room? We have a few (bought used) that don't have a pin thru the extentsion, so it will slide right out. This will let the bases nest. In use, it might be possable to extend it past what is safe, but we are smart enough not to do that. Our bigest issue in the years we have had them, is pick them up by the top, clang.
Compare the base of jack to base of stand. And by the shape, if it sinks, the force will be to spread the feet. A hardwood, or maybe better plywood base would be best. Heavy gauge steel would work as well, (on my tool truck, to jack up loaded trucks, I carried sections of truck frame) and thinner might fit where wood wouldn't fit. But even a then piece would help. Cake pan?
