Welcome to the board and congrats on the new #3! You are going to love it.
Now, I have the 3D - so, I can’t provide details from that, but I do know many on here with the analog models suggest not to watch the internal temp and the swings. They say it will drive you nuts. Even with my 3D I don’t use an internal therm, I just set the digital therm and let it go. So, just throwing that out there. But a question I have on the average temp - is this true average, and not just the median per say? Did the temp actually sit at the high/low temps an even amount of time? I don’t remember anyone posting info like that, perhaps someone has but I don’t, so just curious if that is a true average.
Anyhow - on to that pork butt. Pork butt is forgiving and will take quite a bit of time. And the great thing about a pork butt, if it finishes early, double wrap in foil, then in a beach towel and throw it in an ice chest and let it hold until you are ready to shred it. I always let a pork butt rest for at least 2 hours and add that in to my cook time.
Second - I like smoking at higher temps, no lower than 250F these days. I use to be a 225F smoker, but read other posts and 250F works just as good and is a quicker cook. Some on here with the digital models smoke at 275F, I haven’t tried that but I have on my Weber Kettle and it works great.
And for the last part of your post about the knobs, yes, they can be adjusted from what I have read, but I don’t know what that entails.
To finish, my Dad has a #2, and he cooks at 225F and gets consistent results that are great, and this includes pork butt, ribs, brisket and chicken. I don’t think he has ever tracked the internal temps, but he just sets it and goes on with his lazy Q cook.
Hope that helps. Others will be along to provide some feedback and thoughts. But enjoy that smoker!