That sounds kind of dangerous, even for an aluminum ladder. I think the max weight is typically 500 lbs and that's using it as a ladder ie the weight is bearing on the feet, putting it longwise like a scaffold, I am not sure it was really designed to handle that much non axial weight. the bike weighs almost 600 lbs.
I have found that draping an old burlap sack, which I have dozens and dozens of from my coffee business, over the front chock, it saves the rub marks on tires from the metal on rubber as it seats and it comes out easy peazy now. Will experiment with laying a bag on the flip flop side too to keep from scuffing the tires or possibly chaffing them if you hit them not entirely head on. I think it will work just fine that way as well and be gentler on tires. Tried the paper towel, it worked ok, until it rained, then it was worse than no rag at all. Washing the bike Id assume would be a disaster as well with the paper method.
Aaron