I dented the chainstays on my LHT with a Pleschter double leg kickstand. I might have overtightened, but I'm not sure (I think they sell a product to avoid this too, but I'm not sure about that either). My kickstand eventually broke after using it through a couple of winters (the spring inside snapped).

All that being said, the next time I'm going to do a long tour, I'm going to get another one. I found it extremely convenient.