I did a combination smoker and brewing process controller build recently. In my case, I have 2 PIDs, a timer, 1 SSR, and 2 quick disconnect temperature probes.
For brewing process, currently it only functions as a monitor, but possibly in the future I will use furnace valves to automate (currently using NG).
For smoker process, 120 VAC is passed through SSR and the electric heating element (power output on left) on my el-cheapo brinkmann smoker is turned on and off to maintain temp.
I have a total of 4 RTD / thermocouple sensors. Each one I calibrated to slush water and boiling water data points. The offsets have to be put in each time I switch processes. Regarding the PID "learning" or autotuning, I am sure you could probably write down all of the parameters and input them as needed. I have only autotuned the smoker heating element PID.
For UDS smoker with a fan, you would use the relay output on the PID though, essentially an on/off switch. I have not read up or have experience on this mode. My understanding was that PID learning / autotune only comes into play when operating an SSR and controlling an electric element. I could be wrong through.
Hope this helps!