For several years and thousands of miles, my 1988 (non-basement) Bigfoot sat on a 2x6 front and rear (side to side) with two 2x6s side to side just in front and to the rear of the wheel well. No damage that I can see at all. I have used other methods to raise my Bigfoot, no issues. I have stored it on steel saw horses going side to side. No issues.
I am at a loss as to why your TC is damaged. I wounder if the previous owner used 2x's that did not extend beyond the outside edges of the TC. I never liked having A sheet of plywood under my TCs unless the plywood was cur to go past the edges so the edges were totally supported. Obviously two sheets were required.
Wayne