Yeah, X11 forwarding is only fine on a campus wide network, maybe city-wide at most, if the wan is fast enough.
Sshfs would also be painful for operations processing a lot of data (grepping gigs of log files or even creating thumbnails of images to browse).
Could go old school and build your own:
Page 66: https://www.worldradiohistory.com/AUSTRALIA/Electronics-Australia/EA-1992-07.pdf
Page 126: https://www.worldradiohistory.com/AUSTRALIA/ETI-Australia/90s/ETI-1990-01.pdf