Did they send you a new temp sensor with the new controller? Sounds like that may be the issue with the temps all over the place.
As for smoked cheese, the difference between eating it right away compared to the 3 or 4 week rest is night and day.
And all I'll say on the smoking below 212 is to remember when you are using an uninsulated smoker without a water pan and not a very tight enclosure, the longer the meat is in the cooker the drier it tends to get. Cold smoking works well, hot smoking works well, the temps between 120 and 200 are difficult at best. But you seem dedicated to it so go to it. If you find that sensor is the issue (pretty sure it is) you can adjust your "P" settings at the controller so that your cooker will be more stable at lower temps.
one last thing....want to try some great cured and easy to do meat? Look into buckboard bacon.