i have been dealing with some high elbow issues in my form scince going up in bow weight, and also wondering why my nock point needs to be 9/16 up or a touch higher for good flight and bare shaft planing.  first i shoot ad trads, which at the point end is a fairly large shaft, i also shoot 2364 ash shafts, a bit larger still.  ive been thinking that a high elbow creates more pressure on the lowest finger, i shoot split, which in turn flexes the lower limb a hair more and raises the nock point, but on release that lower limb has more stroke in the same time as the upper and this acualy yanks the arow and nock point down a bit at the point of the arrow leaving the string.
i have done a few things like making my hook a bit deeper and just getting stronger, my elbow is usualy down where it should be and arrows fly wonderfull, but when i get tired i see some nock flight issues and start thinking about keeping the elbow down and equal pressure on the string and it all fixes itself,  but my nock still needs to be a good bit higher than i am used to.
any one else see these things?

Well I would say keep your elbow down if it is putting undue pressure on your arrow.

I used to shoot that way and went to three under and I am much happier

Jer Bear

work on your back tention

I found myself going elbow high when shooting to heavy of a bow.I dropped my poundage and everything came together.For me it was finding a poundage I could comfortably draw and hold without struggling.

Leland

Proper back tension should keep you more level.  Work on that.  You can try 3 under.  I have found that it changes the pull angle and helps me get back tension a little easier.  It could help just work the back tension even if you don't end up shooting that way.

Watch the finger torque and work on a smooth release.  You could be short on draw with the heavy bow, collapsing or plucking.  For me that can send the arrow nock down into the edge of the shelf and force a high nock set to off set, but not fix the problem.

I have to constantly work on the same issue.That high elbow can also increase downward pressure on the arrow with your index finger,especially with shorter bows and that can cause the arrow to smack the edge of the shelf.

My wife had a problem with high elbow, it put strain on her shoulder. I had her concentrate on taking a swing draw and keeping her drawing arm in tighter to the body until the bow was pointed, then finishing the draw with less drawing arm motion.  For her this allowed her to find the stronger muscles.  this resulted in less strain on the shoulder, quicker pointing and accurate out to 35 yards. She developed the problem by needing to try to raise the bow to get on target after she reached anchor, then she would raise the bow arm while the drawing arm was fixed in tension. Just one more thing that Howard Hill had right.