Hi all, This isn't the usual "how to I *insert title here*". What I'd like to know is, have any of you ever had such a replacement/upgrade made after purchase in your local Genius Bar? The reason I ask is that my 2014 Mac Mini (which I bought on eBay) is still in warranty. I know that it's possible to put a PCIe SSD inside of it and build a fusion drive in Disk Utility but I don't want to void my AppleCare! I've tried calling Apple but the support rep on the phone didn't seem to understand my question and was then told by my local genius bar that the upgrade wasn't possible at all as the components are soldered to the motherboard! (I smell something fishy going on here) So, yeah, I'd just like to know if any of you have had the replacement/upgrade carried out by your local Genius Bar. Thanks! Ethan.