For background, the kit enables users to replace an iMac Pro's stand with a VESA mount adapter, allowing the computer to be affixed to any VESA-compatible wall mount, desk mount, or articulating arm. Jason Snell of Six Colors provides a good overview of the installation process in the video below.
Nelson installed the adapter without issue, but ran into difficulties when he went to remove it a few months later:
When I was backing out one of the five screws, which was not overtightened by the way, the screw head just broke clean off from the screw body, and it left the screw stuck inside of the screw hole threads. The end result… I couldn’t remove the VESA adapter… ever.
Nelson acknowledges that the adapter is probably not designed to be taken on-and-off repeatedly, but Apple never warns against doing so, and switching back to the traditional stand at least once seems reasonable.
Unable to remove the adapter, Nelson said he contacted Apple by phone, explained the situation, and was told that Apple could not provide support because the adapter is manufactured by a licensed OEM, despite being sold by Apple with Apple-branded packaging and documentation.
The support representative then declined to provide the name of the OEM or their contact information, according to Nelson, who gave up on the phone call and decided to visit the Genius Bar at his local Apple Store.
Unfortunately, the Genius Bar was not very helpful, as apparently only the Head Genius at that store was trained to service the iMac Pro. Nearly two weeks and one failed repair later, the iMac Pro was finally fixed and ready for pickup, with a new VESA mount adapter installed and the saga seemingly over.
Upon leaving the store, however, Nelson discovered that his iMac Pro's stand had been significantly dented and scratched. The damage prompted him to carefully remove the VESA mount adapter yet again, to see if the iMac Pro itself was damaged, and he encountered similar scuffs on the chassis of the machine.
Moreover, while attempting to unscrew the Apple-installed replacement adapter, another screw broke off, suggesting that Nelson's experience wasn't a one-off situation, and that the screws are in fact prone to break.
All in all, there are two separate issues here: the fragile screws and the un-pro-like customer service that was provided by Apple. And, unlike his fellow YouTube creator Linus Sebastian, Nelson did not disassemble the iMac Pro or perform any other action that would appear to violate Apple's warranty.
Importantly, after the video, Nelson says the Apple Store has since offered to replace the entire iMac Pro free of charge. He was also contacted by Apple's Executive Relations team, which wanted to ensure everything was okay and requested that he send the VESA mounting kit to Apple for its engineers to examine.