I'm afraid we don't have a command line support for editing the requested fields from an updates configuration project. I've added your request on our TODO list and hopefully such improvement will be considered in a future version of Advanced Installer. Thank you for your suggestion.
New command line options are available for editing the updates configuration projects. You can check all our currently available command line options in our "Updates Configuration Commands" article.
New commands that allow you to configure the Update Configuration Project through the CLI are available starting with the version 14.2 of Advanced Installer released on July 26th, 2017.