I'm interested in an SSD upgrade for my 2015 rmbp 8/256. There appear to be upgrade options from OWC and MCETech respectively:
https://eshop.macsales.com/shop/ssd/owc/macbook-pro-retina-display/2013-2014-2015
https://store.mcetech.com/mm/merchant.mvc?Screen=PROD&Product_Code=1TBPCIESSD-2015...