>The XDG config/data spec was made to manage systems that mount over NFS

Which makes sense in theory, but the execution is horrible. The ~/.cache directory is also on NFS now... You NEVER want cache on NFS.

>~/.local would stay on the local workstation

Never seen this in practice. This dir is also created on the NFS share, which it should be, since you need to bring these files to other machines as well. The standard is poorly thought out and poorly implemented.