I'll add my small 2 cents comment just for the heck of it. I use O27 profile track and K-line low-profile switches exclusively. I have absolutely no issues with my post war 2343 Santa Fe, my 2 1960s Lionel steamers, and my modern Lionel By MTH tin-plate Baby Blue Comment and what I call the Christmas tin-plate train.
Both tin-plates, especially the BLue Comet though, have big drive wheels and big flanges, certainly bigger flanges than my 3 older trains.
for what it was worth.
- walt