It's obviously a slightly different combination of technologies, but I've been using NFS over wireguard pretty happily for a while...
It also implements more filesystem functionality, as a "df" report will correctly reflect the remote filesystem's usage.
EDIT: NFSv4 also offers "delegations," which give complete control of a file to a client in an expiring lease; the latest NFS clients also have "polite delegations," which tacitly extend the lease period.
SSHFS is very handy for a "quick and dirty" mount, though, with minimal configuration.
Switched from sshfs to NFSv4+wireguard few years back. Works great!