I use openSUSE Tumbleweed and it has BTRFS and snapper (snapshot manager) set up by default, with all necessary system subvolumes already created. It’s been a great experience for gaming so far, and actually the best experience with NVIDIA drivers I’ve had! All you would need to do is create a separate BTRFS subvolume and snapper config for your games folder and you’d be good to go, without worrying about any other setup! No need to use EXT4 at all. Additionally, there is very detailed snapper documentation on the openSUSE website.