I suspect the code to do the pairing is fairly complex, and putting it into firmware that can work on a computer with NO storage while also not bricking the res

I suspect the code to do the pairing is fairly complex, and putting it into firmware that can work on a computer with NO storage while also not bricking the rest of the machine is more trouble than just requiring a second computer to do all the grunt work. I think I have swapped hard drives three times in over 10 years on my Mac Pro (that I still use!) Also acting like it's extreme hardship for a Mac Pro (!) user to have access to more than one Mac is a bit bombastic. TL;dr - this whole thing is a hell of a lot of fuss for a non-issue for what I would wager is an utterly minuscule number of people. And if you are upgrading a Mac Pro SSD drive, even if you had to buy a Mac Mini, use it once to bless the drive and toss it, it would probably be a fraction of the cost of the SSD you are putting in your Mac Pro and still cheaper than buying a similar sized drive from Apple (even if Apple offered a larger SSD - which is the main reason I would suspect someone would be wanting to upgrade the SSD in the first place).