Fantastic. I did a Google search for the auber pid and found quite a few devices.
Google Search results page for auber pid
They obviously get this issue presented to them as they have a section specifically called Smoker Controllers
Smoker Controllers. They are a little proud of their equipment, and likely so. However, one of the connections I missed in the previous instructions, and I'll need to go back and review, was the temp sensor connections to the external PID controller. Several from this above page offer single or dual "meat probe" connections which would be routed into the box thru one of the existing meat probe pass-thru grommets. I assume this would be the preferred method based upon the need for some type of feedback for the controller to use for maintaining "control" as it were.
Thanks so much for the discussions. I like the mailbox setups, and actually happen to have one of the A-Maze-N tube units my wife gave to me for Christmas a few years back. Was going to use it in the Weber grill sitting next to my MB unit as there isn't a flat surface inside the cabinet to set it on. No big deal there. And as to the 3" hole and ducting, I will need to do an Apollo 13 fix as the current trap door port on the side of my unit for the wood burning area is a rectangular opening, "round peg into a square hole" type of thingy.
My previous MB cabinet was the type mentioned previously with the removable tube that delivered the chips into/onto the burner tray. They offered an optional "Cold Smoke" chimney that sat on the ground next to the smoker that, after removing the tube tray. The smoke exited this device thru a hole on its side that conveniently plugged right into the port the original device used, and was held in place with a j-hooked bolt that hooked onto the internal edge of the smoke chips frame. This external device had a pyramidal chimney holding wood chips with an advertised 6- or 8-hour smoke session. The idea being to provide smoke without having to energize the cabinets heating elements. My issue with that was the chimney accumulated a significant amount of tarry creosote that prevented the chips from falling onto the element thereby preventing the smoke, even tho the thing was full of chips.