Summarize the following:
If there is a longer piece of screw that you can't trim any further, use a nut with the same thread size to hold it in place and prevent snags. Just use a wrench to hold it snugly in place. As an alternative, you can use screw end caps, also called thread covers. These are soft and flexible, making them easy to slide over the exposed end of your screw.

Summary:
Add a nut for longer screws (optional).