A thermapen is a nice addition to you bbq arsenal, although if I were getting a kamado joe, one of the things I would buy (or add to a Christmas list) before a thermapen would be a
I use my thermapen mostly for checking doneness in smaller cuts of meat and probing for doneness on butts, brisket and the like. Although, with the Maverick you can monitor your pit temps and your meat temps remotely while you are in your living room or even better your bedroom sleeping soundly, or whatever else you do in there.
You can set separate alarms for each that will alert you when your meat is done or you cooking temps go above or below your desired temps. I say put them both on your Christmas list.