You just need to think about your load and the product.
Poultry breast is very critical to internal temps,and few other items might be.
Folks may nick a half chicken breast,and if clear,pull at 158*.
Toss in a ziploc for 15-20 mins and they are good to go.
Ribs have a small meat to bone ratio,and nobody knows what temp ribs should be anyhow.
A slab of St.Louis could finish at 2 1/2 lbs,so you just try to keep them warm.
Now you cook eight 16 lb packers at 250*,dbl wrap and cooler,they'll be too hot to touch in 12 hrs.
They could carry up 15 *.
Packers are an experience thing,where good notes are critical.
There are cooks that may cook packers at 350*,and pull when the probe passes all the way thru them.
They let them set out on the table in a cool breeze,to stop the cook,for 20 mins,slice and go straight to the comp box.
This is where you read Smokin' telling folks there are no exact formulas,like frying a 1/4 inch thick slice of bologna , one minute on each side in a 325* skillet,slap a little yellow mustard on some light bread,and you just became a great cook.