Ah ok I understand now. Sibling comments reference the MacOS Library and *NIX ~/.local approaches. Both of those seem to make a lot more sense. Is there a config for Snaps to store user data in a different path, like ~/.local/snap/?
No; they use some magic with security policies and mounts so $HOME/snap is hard coded. Some of the early comments in that "4 year old bug" linked here explain it.
