Tex, I used your method with the TC but ran it under the chaff screen, in through the chaff collector. Prior to this I had it sitting tight next to the Sono sensor and was concerned about stalling right in the middle of 1c (as I was seeing temp swings of 20~F). Running it all the way down into the glass chamber gave what I think to be much more accurate temps by a difference of around 20 degrees. Also, when the gas would cycle I'd see temp drops of 5-10 degrees as opposed to the 20. I'm guessing internal bean temps to be a bit less than that.
Were you concerned about running the TC over the glass and leaving a gap in the seal between glass/ o-ring? I will try that next as when using my method, it's kind of a pain to extract through the chaff collector and while doing so it makes more chaff fall down to the beans. Not a big deal with a shop vac handy but takes another minute or two.