Yeah, the camera attached directly to the bone’s socket (without spring arm) means the position of the camera is the same as the socket and doesn’t change through time. This asset takes advantage of that and doesn’t re-calculate the position of the camera every frame, it’s just a performance consideration, but re-calculating it every frame is perfectly ok and won’t cause noticeable difference in performance, unless I guess if you have a very high amount of characters doing that in the game.
But, if you want to use a spring arm you can, you’ll just need to change the code to re-calculate the position of the camera every frame, instead just calculating it at the beginning and never re-calculating it again.