I'm smoking this chuck roast on my pellet smoker, just like the Camp Chef 36 smoker or Traeger 780. Pellet smokers are an easy and great way to impart fantastic smoke flavor on the beef, something you won't get from cooking in an oven or slow cooker.
When the meat reaches around 150°F you might see it stop rising in temperature as quickly. This is what is called 'the stall'. This is normal, you just have to wait it out and let the meat do it's thing.