Remember, the larger the curve, the less overhang that you'll have on any locomotive. I have an O90 curve on my second level and a post that's 3.5" from the centerline of the track. The biggest overhang of my fleet seems to be the MTH Premier Big Boy at about 3.25", and it clears the post easily. The next guy that's about as close is the C&O Coal Turbine, at 26" long, it's the longest locomotive steam or diesel that I have.
I suspect you'd find that the LC+ 2.0 Big Boy would have no issues at all on your wider curves.
I have a store front that protrudes towards the 096 rails on a curve and my Lionel Berk clears by a thread.