What's "modified" Weaver to you?
Too, about ten years back I started having trouble with my right shoulder. Over the years, got to the point I couldn't work with arms raised above shoulders. The motion of just raising my right arm to shoulder level got painful. Anything I had in my hand that added any weight made shoulder hurt worse when raising.
Though's of you that have had Rotator cuff trouble know where I'm going with this.
At any rate, there was not any kind of modified stance I could come up with that would enable me to draw and shoot. After while, it even hurt to stand and fire pistol without drawing. Just holding pistol up hurt.
End result was what the doc. told me many years prior, Rotator cuff surgery.
Should have had it done years prior when Dr. said to have it and I wouldn't have had to endure the progressive pain.
You know the old saying "Hard head makes for a soft Gluteus Maximus"