I have used them for years without one issue..The reason I use them is when my very large boys come stay and sleep in the slide part.Were talking over 200 lbs per kid horsing around as kids do.
Used properly they cause absolutely "No Damage"..I have even had a flat tire when they were deployed and they did not move or cause damage because the coach was "properly" supported.
Virtually every RV retailer sells them with the intent to damage your RV..Ya right!!!!
Used correctly they work great for extended stays where I use them the most.