Ok. Finally got a minute to explain what I was saying better. The fact I own an actual chalkboard instead of doing this on an I-whatchamacallit might get me a little traction with Brent.
Ok. So ideally a bow is 2 giant springs. To get the most efficiency out of the cast you want them to pull evenly and spring back evenly.
Like this.

Bow is held dead center. Pull on the string is dead center. Arrow is dead center and 90 degrees to the bow.
We can't do that... Your hand is in the way.
Center of a recurve riser is usually at the top of your hand depending on design. Might be higher might be lower. To high or low and the bow torque on your hand becomes palpable.
Any way you pull a bow the arrow is above center. On top of your hand or on a rest a few inches up or anything in between. So we compensate depending on how you shoot.
Split fingers. If we weaken the upper limb just a touch it pulls straighter then at full draw because your grabbing above center string. Arrow above center slightly. Your grabbing at the arrow. Weak top arrow stays pretty straight. The CLOSER I can get that arrow to the top of your bow hand the closer to the center of the string you are pulling the less I weaken that limb.

But you can see what would happen if you shot split finger with the arrow 1 inch over center. You pull the bow pretty unevenly and lose efficiency. By the way Brent, yes a Bear bow is most likely set up this way. Off the shelf split finger shooter.
3 under. Now I'm pulling really close to center sometimes right at center. So I get spring efficiency like the top photo. Buuut... fingers and hand are in the way of the arrow. The arrow is on top. So if I raise the shelf or rest up a tiny bit to make the arrow again straight with the shot, I get good flight. Still need a weaker limb but not as much. Sometimes no weakness.

Not a bad choice either. Olympic guys shoot under the arrow. String walkers also.
And we're talking about TINY adjustments here. 1/16 to 1/4 inch tops. But knowing which ones to make, how much, and when to make them is what makes a $1400 custom built for you worth it. There's a lot more that goes in to custom to you bows and how we weaken limbs but that's all I wanna give away.
I shoot 3 under because I have a shorter index finger... more comfy. That's it. Either way is up to you as long as your consistent.