So, does putting it in the cooler keep the meat cooking longer or is it just to keep it warm?
Jim, any time you wrap & rest meat, whether it be in a cooler, or just 10-15 minutes on the counter (like I do steaks), you will have carry-over cooking. The meat continues to "cook" for awhile, usually rising in temp no more than 5°. Then, it stops cooking, and begins to slowly cool. All that insulation
really slows the cooling process! This is the time when the outward flow of juices stops, then reverses, and begins to be re-absorbed by the meat. Magic, my friend...pure magic!