I shoot split fingers, and have a two point anchor: feather touching my nose (5" shields), thumb knuckle o my earlobe… very similar to what you were shooting 3 under. It seems to work with parabolic fletch also, as long as it's cock feather out.
Not so with banana fletch, or anything cock feather in. i do like to experiment - and have - and do - but consistency is consistency, so I need to spend some time with something to see if it works. if it does, I stay with it until, or unless, it doesn't. It also has to feel right. So this is what I've been doing for a while.
Comes back to the same consensus - find what works for YOU, and try to seek repeatability.
Just my .O2.