Some comments
"That's why we installed all available Windows updates first – to ensure the latest firmware was installed before we began."
Personally, I would have used the Lenovo System Updater and not bothered with the potential hours long Windows Updater. After all, it's only the firmware updates you want and you can easily choose just those from the OEM updater.
"We had to choose Wayland on the login screen in order to get display scaling to work, which is a necessity for the HiDPI display: without it, at its native resolution, text is too small to read."
Global scaling is a relatively new innovation. All the other scaling options, such as choosing icon fonts, toolbar fonts etc are still there. Did they work? The artcile doesn't mention iof that was tried. I would normally not use global scaling because often it's not quite what I want. Making the fonts the size I want means the icons then become too big, so being able to scale stuff manually and individually is how I prefer it anyway.
"rendered the machine unbootable, necessitating a full reinstall, starting with Windows 11 22H2."
That's a surprise. Linux is usually pretty good at sorting out screwed up partitions by, at worst, allowing a wipe. I have seen systems on rare occasions where the boot blocks and other stuff in track 0+ is so badly screwed, the best and only real option is to boot a live OS, Linux, or even Windows these days, and write zeroes over the first few hundred or so blocks making the SSD/HDD seem like a factory new drive to the OS. Was that tried before spending time on an entire Windows install? At the very least, if the Windows install "fixed" anything, it would be safe to just kill the power as soon as the SSD was successfully partitioned, no need to do a re-install.
"the X1 Carbon only has four USB ports
That's one or two more than many laptops these days :-)
The target market for this laptop, I'd expect them to have a USB->ethernet adaptor in their kit. It's an issue with many makes and models of slimline laptops these days. The flip out RJ-45 connectors are great. Except the non-technical users tend to break them with great frequency.
"enabling us to reinstall all those Windows updates – now well over 60, including various drivers."
Again? Why? You already did that once. Any firmware updates useful with the Linux install are persistent and you did them. If drivers are also installing firmware "blobs", and you think you still need them, then they are only used when the OS boots and are lost when you power off or install a different OS.
The best way to see if a Lenovo is likely to have hardware support in Linux before installing anything is to boot the Lenovo Linux Diags Tool and see which of the diags tests are greyed out (might just indicate that hardware does not exist on your model of course). If the diags for the hardware works, then Lenovo, at least, have got drivers for it and so is likely to be available "in the wild" too.
I'm trying not to be too negative over what is a decent review overall, but the points above just struck me as really odd and likely off-putting to someone unaware of the potential pitfalls.
I don't work for Lenovo. I just happen to have a number of customers who use lots of their laptops and I have to deal with that and so have gained a lot of experience, especially diagnosing and dealing with hardware issues