I tried to run my 4010 cargo train (RC mode) on my "around the Christmas tree" LGB track layout, but the engine would constantly derail on the switches and 30 degree crossing - I used this layout modified with a few 4 additional straight pieces added to make it a bit larger and added 3 switches to create side yards for keeping cars:
In reading other forums, it appears the flange on the RC trains is a bit larger then the electric ones, so it causes the wheel to rise when going over LGB switches.
So... did you have to reduce the flange side on the other set of wheels on the engine or does it seem to run smoothly on the electric track?
Thanks!