You’ve been around here long enough that you probably understand the basics, but in case you don’t here they are.
There are two “things” to work on for penis enlargement, the ligaments that are attached to the penis and keep it (when erect) in the correct position for intercourse, and the tunica albuginea which is the tough covering of the erectile chambers in the shaft. Stretching and jelqing both work on ligs and tunica, but stretching is directed more at the ligaments. Girth gains come primarily from enlarging the tunica and that’s what the jelq works on. Length gains also come from jelqing, but if you’re concerned with girth, then jelqing (and later more advanced exercises) is the thing you want to concentrate on.
So, to answer the question, you can do anything you want. If you don’t want to stretch, that’s OK. Just be sure to get your penis conditioned to exercises before you try some of the advanced girth work.