I would skip the sausage hanging stuff and just cut them to fit and lay them horizontally. That is just my opinion as I think you'll get a more even cook by doing it this way and then rotating your trays periodically top to bottom and front to back. My smoker has a hot spot in the back, so rotation is a must. You can see a couple of pieces in the packaging picture below that got kinda burnt because I didn't do a good enough job of rotating. But out of 50 pounds (2 batches), I think we only had 3-4 sticks that weren't edible.
Between my Dad, Brother, and Brother-in-Law, we smoke about 250lbs of snack stix a year depending on how many deer we get.
We cut our links in 40" sticks and hang them on my "Sausage Rack 1000" which is just a hanging rack that I came up with. We let them rest overnight and then just lay them horizontally on the racks. I have never bothered trying to hang because the 25-28 pound batches that we do would not fit if I hung them. I can just barely get 25lbs in on 6 racks. So, my smoker is maxed out. I think the #3 is just not quite tall enough for hanging. The #4 on the other hand is a different story.
Other than the first two hours, yeah you will need to use the dyer for the entire smoke. You will be amazed at how much steam needs to be pulled out of the smoker.