Does anyone have experience with a Reverse shoulder replacement?

I think it is mainly to keep your arm from being accidentally bumped. I suspect that natural, gentle movement is probably beneficial in returning to better end results, rather than keeping the elbow cranked up all the time, as long as you don't put yourself in situations where you might wrench it. I had an immobilizer instead of a traditional sling, which allowed me to disconnect the wrist strap and use my hand in the forward position, but still kept my elbow strapped to my waist. My surgeon said to keep using my immobilizer when going outside the home for a couple of weeks after discontinuing it at home so that well meaning people would not bump or grab your arm.

I have had bilateral total reverse shoulder replacements. I lived with severe pain for several years before surgery. It is one of the more painful surgeries but the end result is why it is worth it.