I have shot both, and find that I am more accurate three under. I think, for me, the increased accuracy is because I can get 4 points of contact at anchor and for split finger I get 2.
The only reason I have switched back and forth a couple of times is because I like how the bow is more "dead" in my hand when shooting split finger.
If you switch, or goof around with it, which I think you should, I would suggest you do it way in advance of any hunting you may do. When I am hunting I want everything to do with the bow to be "natural" and I don't want to think about "choosing" three under or split.
Have fun. And if you do try, just get over how "goofy" it feels. When I switched the first time, I literally felt "yuk", as it felt that unnatural and weird. I got past that and now three under feels natural.