@xakraz hibernation wasn’t working, the wiki to enable this on BTRFS filesystem is updated and now it works again. I have updated my script. More info here:
The Arch wiki articles on how to enable suspend-then-hibernate are incorrect, this suspend-then-hibernate isn’t even a supported value in sleep.conf and logind.conf, contrary to what the wiki says. The only way to get it working is by symlinking it to the suspend service. See my script.
You can still also enable hybrid sleep by changing the State in sleep.conf to disk, but it is less useful with the way suspend-then-hibernate now works.