But that’s not an issue because of that support. If your hardware is failing, then that warranty and support will make it their problem, not yours.
Side comment: You’re right that Tier 1 vendor custom builds are limiting, though. I consulted with a company who had bought an IBM workstation with a Tesla. The workstation was even configurable for dual Teslas, but they bought with just one card. I wanted to add a second GPU, and lo and behold IBM had used a custom PSU with exactly one 6 pin and one 8 pin power cable, so I couln’t just add an extra. And the custom PSU form factor prevented swapping it out, and IBM didn’t sell the “two GPU” PSU separately. I ended up using one of those 5.25" drive bay aux PSUs to drive the second board. But only after digging up a PCI video card since the motherboard only had two PCIe slots! It turned me off of such custom machines… you get what you pay for, but absolutely nothing past that.