For those of you who like to boot off of you btrfs snapshots using grub,
eos-dracut 1.2 now contains support for adding an overlayfs when the root filesystem is a read-only btrfs snapshot.
This does not require any special configuration.
Once you update eos-dracut and rebuild your boot images, any future snapshots will automatically support the overlay.
Will something like this also become possible for systemd-boot?
It would be possible to add this support for systemd-boot but it wouldn’t currently be useful since systemd-boot can’t properly boot snapshots in the first place.
It would take some significant development to get systemd-boot able to boot snapshots on Arch since old kernel versions are not maintained.