Backups are more useful for disk / file system failures rather than rollback, there are not many issues that cannot be fixed on an Arch rolling system.
Tip for anyone using Clonezilla to backup luks partitions. It uses dd by default as it cannot detect a file system. This takes way longer than it should and the resulting image file is way too big.
Better to manually decrypt your luks partition first and use partclone to image the file system, not the entire luks partition.
To backup a luks partition ext4 file system.
sudo cryptsetup open /dev/sdXX crypt
partclone.ext4 -c -s /dev/mapper/crypt -o /backup-disk-path/backup-image.img
sudo cryptsetup close crypt
To restore a luks partition ext4 file system.
sudo cryptsetup open /dev/sdXX crypt
partclone.ext4 -r -s /backup-disk-path/backup-image.img -o /dev/mapper/crypt
sudo cryptsetup close crypt
This is also useful if your luks headers somehow become corrupted and the partition cannot be decrypted, simply create a new luks partition and restore the file system into it.
Partclone supports most file systems.
pacman -Ql partclone | grep /usr/bin
partclone /usr/bin/
partclone /usr/bin/partclone.btrfs
partclone /usr/bin/partclone.chkimg
partclone /usr/bin/partclone.dd
partclone /usr/bin/partclone.exfat
partclone /usr/bin/partclone.ext2
partclone /usr/bin/partclone.ext3
partclone /usr/bin/partclone.ext4
partclone /usr/bin/partclone.ext4dev
partclone /usr/bin/partclone.extfs
partclone /usr/bin/partclone.f2fs
partclone /usr/bin/partclone.fat
partclone /usr/bin/partclone.fat12
partclone /usr/bin/partclone.fat16
partclone /usr/bin/partclone.fat32
partclone /usr/bin/partclone.hfs+
partclone /usr/bin/partclone.hfsp
partclone /usr/bin/partclone.hfsplus
partclone /usr/bin/partclone.imager
partclone /usr/bin/partclone.info
partclone /usr/bin/partclone.minix
partclone /usr/bin/partclone.nilfs2
partclone /usr/bin/partclone.ntfs
partclone /usr/bin/partclone.ntfsfixboot
partclone /usr/bin/partclone.ntfsreloc
partclone /usr/bin/partclone.reiserfs
partclone /usr/bin/partclone.restore
partclone /usr/bin/partclone.vfat
partclone /usr/bin/partclone.xfs