Good to hear you are finding out the cause of some restrictions and what is/isn’t possible within your situation.
Great that you are seeing improvements where improvements can be expected.
I would agree that surgery for the sake of surgery isn’t a good idea. Where it healed incorrectly many years ago this limits options and outcomes with opening it up again.
Learning to work within your ranges and feeding as much slack as possible will allow you to get the most out of the situation. Yes there may be some skills you aren’t able to perform, but its not from a lack of trying. There is a mechanical restriction that won’t allow it. So focus on what you are able to do.
Feeding slack from the elbow,lateral seam, and tricep can help to improve position if these areas are tight.