Useful but the length of this would scare me away from trying this. I have followed these instructions for years now although I will note I normally only have an os installed for around 1 to 3 months
This is the method I use, if its the same sorry but that videos was too long
sudo pacman -S grub-btrfs
yay -S timeshift
yay -S timeshift-autosnap
sudo grub-mkconfig -o /boot/grub/grub.cfg
And then I run timeshift once and configure it and it seems to work, have had to use once and worked as expected