Like all smokers out there, someone is always tinkering with them, and that's certainly fine as some just feed that need
However, any changes WILL violate your warranty, so beware.
As I always suggest, just email or call CS direct and talk to them about your ideas. They have made slight changes over the year, but they don't monitor the forum a lot, so calling them is best.
FWIW, the meat doesn't care about the variations. While lots of people seem intent on getting their smokers +/- within a one degree range or less (several threads over the last week in a couple of other forums) the meat could care less. It's really the average temp, +/- XXX and it still comes out tasting great.
I love my FEC"s that they stay within a small temp range, but I don't sweat it whether it's 1, 5 or even 10 degrees, it's the average I want.
What did we do before we had all the electronics...LOL
Oh, and a PID controller, what is it (hey, we're bbq'ers)
Check out wikipedia, even has the formula for us math types:
What's a PID