Hi there. EricD hit it right on the head. Butterflied, aka spatchcock, chicken will cook a lot faster. And you can't really think of cooking food items in a manner of hours per lb. A 10lb ball will take a lot longer to cook that a 10lb sheet because the conducted heat will take longer to travel to the center.
IMO, I don't believe the smokenator is the issue. It's just a tool that needs to be learned. You can just as easily destroy a cook with a roti or nothing at all. Learning your tools at hand will be your key to success. That being said, I personally do not have a smokenator and would have cooked that bird at around 325-350 for however long it took to get to 165-170. Or 180..depending on who I'm serving to. I have had "complaints" of the chicken not being cooked and or being a bit pink at where I find the chicken to be good. Despite my assurances it's cooked to temp, I bring up the temperature to avoid the initial shock from my guests. I'd rather do that then have them "concerned." I digress... 26r, snake, fire bricks, smoke chunks, 325-350, temp probe in the thigh, cook till done, hit it with thermapen to verify, rest till I get other food items plated and guests seated, carve and serve.
Now to another matter. I personally think it's not a good idea to have the temp controller when starting. I don't know your level of grill aptitude, but I feel like it may serve you better to get to know your cooker and how it reacts before you throw controls on it. If that thing fails in the middle of a cook and you don't know how to control your heat without it your fuqt. Get to know your grill first then add the tool on top if you feel you want it later or it will be a crutch. A maverick dual therm or a ThermoWorks dual therm would be money much better spent IMO. And you can use either one of those in the oven also.