Great info. But this best belongs in a man page (or some other relevant document) in sysutils/sshfs-fuse, considering OpenBSD’s reputation for high quality documentation.
I don't think that reputation applies to stuff from the ports tree, which is by definition not OpenBSD.
Not really, but several ports do have OpenBSD-specific documentation added by the port maintainer. I agree that it would be nice to put this information in the port.