I can’t say what will get support. You’ll have to get that from the Discourse team when they’re back in the day time.
While you wait for a reply from the Discourse team, then why not try out option 1. If everything installs fine then you can check that it works perfectly before going public. Option 2 would be your fallback if option 1 doesn’t work OK and you cannot resolve the issues.
One caveat is that the guide is over two years old - last edited April 2016. Since then there has been at least one problem identified. This problem with SES email was resolved but I don’t know if other problems are out there: