The tires are obviously different. The 31AG and seen-once-only DF-41 has the off-road tires. The paraded 41 has the road tires. That probably means that they are prepared for all sorts of operation conditions, just like passenger cars in north have winter and summer tires.Look at the tires.
There are said to be 2 types of TELs for the DF-41. Road mobile plus underground tunnel version and an off-road version. DF-26 and DF-31AG TELs are off-road capable. There is a single image of a DF-41 TEL that has the same tires and said to be the fully off-road capable but we never saw that again -
But the TELs are the same HTF5980 (A/B) having the same capability (engine power and suspension)