I had a PVC fitting in the hole for my Maverick probes about 4 inches down from the rim of the barrel. It burned out and fell out after less than 6 months of use. The pvc nut was brittle and had cracked due to the heat. It just fell off one day when I was inserting the probes through it for a cook. I now just wrap the probes in foil and plug the hole while cooking. Works better that way.
I think the heat will be too great for direct input into the sides of the barrel, and that a steel pipe elbow would be better, and then use the PVC pipe for the standpipe. I also tried a 2 inch PVC section for my exhaust coming out of the 2 inch bung hole, and it became brittle in a short time. I replaced it with a steel nipple and all was good from then on.
UDS, cheap o grill, rusted chimney, yeller wannabe thermo pen, Maverick ET 732, 1950 model wife.