Ah yes, that's clever:

    $ sh -c "$(quote-argv -echo 'file with spaces')"
    sh: 0: Illegal option -h

    $ sh -c "$(quote-argv-left -echo 'file with spaces')"
    sh: 1: -echo: not found

Over ssh:

    $ ssh example.com "$(quote-argv-left -dashtest 'file with spaces')"
    -dashtest
    file with spaces