Get (if you don't already have) a large external transmission cooler. Get the largest one you can fit; don't worry about the rating.
Keep the bands adjusted as well. The 46RE / 44RE aren't known for their excellent durability, but aren't junk transmissions either; just sort of "ok."
54k miles isn't much, but the 2500 is a large and heavy truck and can be subject to hard work / towing. If you aren't the first owner, you likely don't know how the previous owner treated the truck.