I agree, this is why I keep separate /usr partitions, both to allow for growth, and to monitor my growth. Another weird thing Arch has such a difficult time booting with a separate /usr, more like the dev's ass-u-me again no one will *ever* do this...
I started doing it as a means of checks for watching growth over the years. In the old days of 8.04, usually a 4gb partition for /usr was fine, and less than a gig for actual root (/). Now I fill /usr with at least 6gb of data on install it seems, 7-8gb is more the norm.
Use of GPT is/was really trying to keep up with tech, where early days of SSD, fdisk was terrible about alignment, where most things can and still do say to use GPT. Just no one tells you it is inherently broken still on most platforms to consider booting off of.
I'd be more inclined to try EFI, but I'm fond of consistent raid approaches, even for boot partitions, where the inflexible FatFS nature of EFI partition just rubs me the wrong way as it can't be made natively redundant like I can with /boot being on mdraid partitions happily booting linux otherwise. Curious what others do with redundancy around EFI desktop drives...
Even without another shed of M$ on here, it still finds a way to screw things up.
-mb