If you are looking at the package directions, that 4 - 8 hours are directions for applying TQ to thin cuts of whole muscle; chicken, pork chops, ribs etc. Those directions have nothing to do with sausage making.
When adding a cure to ground meat, as long as you mix everything well, you don't need to wait until you stuff it. The curing action start immediately, and by chance the curing is not complete by the time you place it in the smoker, during the drying period the low heat will speed up the curing. Mix the TQ with the liquid that is called for in the recipe, before adding it to the meat. Whether I am using a cure or not, I stuff immediately, because the salt will stiffen up the mixture. Also after stuffing, it is generally too late for me to begin smoking the sausage, so I generally refrigerate the stuff sausage over night. I feel this helps develop the flavors.