You might want to shorten it up a smidge, but first consider this. Pulling the shoulder blades together forces many people to pull their bow arm inward also. While the string hand is pulling back, the bow hand winds up moving back with it. So the back tension is never transmitted to the release trigger.

What I recommend you try first, before adjusting your release length, trigger tension or anything else, is to concentrate on pushing your string hand elbow straight back while pushing your pin straight into the center of the target. Do that rather than trying to pull your shoulder blades together. That movement will isolate the muscles on your string side and allow them to move independently of the bow arm back muscles.