Here's how I do my chuckies. Works for both my UDS and WSM. I put the chuckie on at qbout 260*-275* Depends on were the unit settles. Keep it there until it hits 160* IT. Then add it to a pan of broth and veggies, cover with foil and put it back on until the roast is probe tender. Now the advice above will save you step 2 on the veggies, but you still have to cook the chuckie to probe tender. So, either way you got another 2 to 3 hours of cook time. the chuckie will braise in the sauce and really get moist and tender. I usually let the roast rest for at least 1-2 hours and then shred. I think your trying to move things along to fast to get a really good outcome. What your trying to do could have been done in a crockpot and ready for dinner. Smoking it is a whole different story. Once you have smoked chuckie, you'll break your crockpot.