Want a fuller Christmas cactus—prop or wait?

I got a single cutting of a Christmas cactus in April of 2022. It has since done really well and grown quite a lot, as you can see in the photos. I would like to start to fill out the plant more to establish a bigger cactus. This is my first Christmas cactus, and so I am unsure what the best route would be.

In one of the photos, I have shown that there is a little air root reaching out. Is it best to try to propagate that piece of the plant? Any advice is greatly appreciated!