I'm not embarrassed to ask stupid questions any more, so here goes. What are you considering and unacceptable temp variation? There was a time when I would freak over 10* and start adjusting everything. Now, a bunch of years and cooks later, I pick a desired cook temp and set my iGrill alarms at about +/- 25*; so for a 300* cook I'm happy to stay in a 275*-325* range and I use the lower 275* alarm to remind met to throw a split or two in my stickburner. With all the new gee-wiz stuff out there, even for us old stickburners, it's way to tempting to try and "micro manage" the cooker, just sayin.
Weber 26.75 OTG w/CI grates & SJ/WSM Mini
Home built 24"x72" reverse flow stick burner trailer with 18"x40" grill w/CI grates and upright SS gas oven/smoker.
Home built 48" fire pit with a 30"x30" Santa Maria style ranch grill.
Home built lump charcoal retort, iGrill & a bunch of other cooking toys.