something to consider, perhaps ...
instead of 3under, you might wanna give the "flemish 2under" a try. this can be done one of two ways - pointer and middle finger under the nock, or middle and ring finger under the nock.
consider first that with split finger, the vast majority of the string's holding weight is on your middle finger, with some on the ring finger, and the least on the "arrow nock holder" pointer finger. this feels most natural to most archers.
now, if you flip over your string hand palm up, and open your fingers, it's the middle finger that's in straightest alignment to the wrist and forearm bone. notice that the pointer finger is off at an angle, and if you force it into alignment with your wrist and forearm, your hand juts off at an angle and is fully out of natural dynamic alignment.
your arrow MUST nock UNDER the string's nock point. your arrow's nock MUST LIGHTLY hang onto the string.
so, with your normal spilt finger tab or glove on, nock an arrow. split finger the string as you would normally. come to full draw as you would normally, making sure that the lion's share of the load is on your middle finger. totally relax your pointer finger - it can lightly touch around the string without holding the string or it can be pointing forward and not touching the string. aim and release. it might feel different at first, and you may have some some follow up questions. for sure, it will allow for a cleaner release than split finger, and that will allow for more accuracy. flemish 2fingers will also be less jarring than 3fingers because it's more like split finger string hand finger alignment but with one less finger to drag and yaw the string.