The problem with going back and forth, is that when shooting three under, sighting with the arrow gets convenient and then going back to split, it seems like the floor falls away from your perspective. Then the tendency to lose the feeling of your split finger aim and you can start to over think and second guess yourself. Long years ago, I shot three under with a short recurve for a couple of years. I liked how out to twenty yards how I could group a little better by gun barreling the arrow. I did notice that the bow felt a bit more harsh and that if I tried to increase my shot tempo my release got harder, perhaps pulling more with my ring finger, which had major effects on my arrow flight. I had lost the ability to make a quick controlled shot at pheasants and rabbits. In the end, I decided that I was back to the same timing and shooting situation problems that I had when I had sights on my recurves, which limited me to being able to only shoot at game that gave me all the time in the world to make a delicate shot and from the same shooting positions. I tried three under a couple of years back with another short recurve and had terrible arrow control problems, I had to be oh so careful to not lift the arrow off the shelf with my draw. I once missed my target, missed my garage, and luckily hit my house. Some find it perfectly natural to go three under and can shoot that way in diverse situations, I, obviously am not one of those people, I always get into situations where I need to do something a bit different to get off a good shot. If you are not ready to make a permanent switch, try visualizing your shots and everything familiar about your shot, before drawing the bow. I find that I must do this every so often when shooting to keep myself focused and consistent, otherwise I start to need to force myself back to form and aiming control halfway through the shot process, that never works for me.