Chuck shoulder is not done when hot; it is done when collagen melts.
Covered cooking is mandatory.
Season heavily; a roast this size takes far more salt and pepper than most cooks expect.
Texture is the final doneness test; internal temperature near 200°F is a checkpoint, not a guarantee.
If the roast is tight, re-cover and keep cooking.
Lower oven temperatures hold the roast in the tender range longer and are harder to overcook.
Roast holds covered in a 170°F oven up to 4 hr without drying out.
Flavor improves after resting or overnight refrigeration.