I once asked a CM about running backwards, but they never said anything re:crossings. What they said, though, was that while it isdoable, it caused wear and tear on the couplers back in the 90s and it wouldn’t be ideal. I’m not entirely sure where she was getting this from as I’ve done plenty of model railroading in different scales and even have the opportunity to play with 7.5” gauge trains every Saturday when I’m in chicago, and have done some shoves, but never worn out a coupler. Not that it’s not possible, but it’s certainly not common. Unless of course the couplers that the Walt Disney World Railroad use are different (they certainly look smaller) and more fragile (the second part which is HIGHLY unlikely)