Never used a therm on ribs, either. I think you'd be very hard pressed to smoke ribs by temp...finding the right spot to insert the probe between the bones, getting that same position every time you probed, and, either finding a proven method or creating your own and making it work, 'cause, I've never heard of anyone using a temp method to cook ribs...way too complicated, IMO.
KISS method works best for me...low & slow until everything looks and feels right...pull-back, bend test, etc. BTW, I did some higher temp cooking with spares a month or two back, just for giggles and what if...started @ 320-330* for the first hour, dropped back to 275* for the remainder of a 3-hour cooking time, instead of my typical 6-7hrs. They looked OK, had a fair amount of shrinkage/pull-back, but tenderness was totally lacking...a ton of chew all the way through. When reheated the next day @ 225* for nearly 2 hours in a covered pan, a bit more pull-back showed and they were far more tender, so the slower reheat turned 'em into much more edible ribs. Can't rush 'em, just like brisket or butts.