Unfortunately, HostGator doesn’t currently support CLI version of PHP.
In addition, I’m actually having to use using phplist 2.0.6 (!)
However, after I contacted them today, they are upgrading to the latest supported version of phplist, which, as I understand supports a secret mode (?), that may at long last allow me to set up a cron job that will actually run. Although I will need to do a deep dive into whatever that variant requires.
Thanks for your input.