Sting a bow and measure tip to tip. Find the middle of the string length and compare it to the location of the bow hand on the grip and the nocking point. For most bows you will find the bow hand is largely below the center of the string and the string hand, especially for split finger shooters is above the center of the string. For most bows this means the upper limb will be worked more than the lower when the bow is drawn. So most bowyers make the tiller for the upper limb larger or 'taller' than the lower limb. Also called positive tiller. Ultimately, the bowyer is trying to get the geometry of the bow worked out so the limbs return to brace height at the same time when the bow is shot. This gives the smoothest shot feel, best transfer of energy to the arrow, etc.
The three under shooter places their string hand the width of the forefinger and thickness of the arrow nock lower, or closer to the center of the string length. So if a bow has been tillered for split finger it's possible the geometry of the bow will not allow the limbs to return to brace height at the same time when shot three under and using the split finger nock height. The bow can vibrate more, and make more noise since the limb timing is off.
One way to compensate for this is for the three under shooter to raise the nocking point to getthe string hand location closer to the split finger set up. Another approach is for the three under shooter to use an elevated rest and raise the nock point even more as a result.
I don't find most Hill style longbows very sensitive to split or three finger shooting. I think the length of the limbs makes the bow more tolerant of changes in the string hand location due to split vs. three under holds.
There are other variables in play as well. Consider grip style and contact location of the hand. Some folks, especially with recurves, shoot with a high wrist grip meaning most of the contact with the bow is on the web of skin between the thumb and forefinger so the contact area is fairly close to the center of the string length. Most, but not all high wrist shooters can use a lower nocking point than folks who use a very low grip. Most longbows are built to shoot with a low wrist grip with most of the contact area being along the base of the thumb. Since the center of the contact area is lower than a high wrist a higher nocking point is often used.
I've not found a huge difference on recurves either. More than longbows, but no so much that a recurve tillered split cannot be shot by a three under shooter, especially if the nocking point and rest height are changed.
If you are getting a new bow, and want to shoot three under, let the bowyer know. He or she will know what if any adjustments are needed to get the best performance for your shooting style.