You have to keep the original one in case for Warranty. I had a chat to my Apple Business team, they can't see if you swap the SSD or not. So you still have warranty on the device as long you don't break any components by yourself.What are you guys doing with the original SSD? Is it possible to place it in the secondary slot to use for data etc?
Had a look on AliExpress now, looks great but one small detail is missing. They won't provide any Invoce. The Invoice is a simple sceenshoot (i made a test purchase) which wont be accepted by tax Companys in Europe if you buy it for Business@terratoss lf you scroll up the posts you will find our comments and links about the SSD from ALiExpress. I have the 8TB with no issues for almost a month now.