Complying with the XDG standard seems about as good as a stringly typed OS like Unix can get. Part of which is making sure that the defaults the program choose

Complying with the XDG standard seems about as good as a stringly typed OS like Unix can get. Part of which is making sure that the defaults the program chooses may be overridden by consistent environment variables. Programs need some way to persist their own state and configuration, after all. The fact that XDG is more honored in the breach is tiresome, but this can at least be corrected, and it's well enough put together to be a steady-state approach to wrangling dotfiles.