So, just to finish up that tangent about updating ... I ran PC Health Check to see what the actual no-no is for Windows 11 on my machine. Apparently, it's just that TPM 2.0 is not available or not enabled. My machine is a custom build, which could be the reason for it not being enabled. So, if I were really keen to update, there's a chance I could do it. But as I said, I'm really looking forward to going back to Linux.

-- I'm not mad at you, just Westphalian.