My iPad Pro 12.9 first gen (2015) still rocks on iPadOS but the battery is down to 80 percent capacity according the Apple Genuis Bar. I understand the battery replacement service from Apple is 99 bucks and they don’t swap the battery but replace it with a refurb unit. Has anyone had this done before? Of course my hope is they don’t have first gen refurbs and give you the 2017 model. Thanks...