ah, ok.
nothing that comes to my mind i regards of snapshotting @home. Putting ~/.cache in a separate subvol is indeed a good idea then.
Just some things to consider maybe about btrfs for the home partition in general. Like, if you use VirtualBox or the like, one should disable CoW für the VM images (or the containing folder). Those VMs usually reside in your home directory.
→ https://wiki.archlinux.org/index.php/btrfs#Disabling_CoW
same goes for DBs.
I think there also was something that does (or did in the past?) not support the btrfs filesystem. But i can’t remember if it was Steam or the Dropbox Client or whatever…
Yeah, i would also recommend this.