How do I push the test site back to my main site / production site? \u000aIs there a mechanism to push seamlessly, or would I need to use a migration plugin as with any webhost?

Hello! A plugin such as this one is recommended for migrations:\u000ahttps://en\u002Dca.wordpress.org/plugins/all\u002Din\u002Done\u002Dwp\u002Dmigration/\u000a\u000aOr you may also use SFTP. Each Squash instance has their own unique SSH/SFTP endpoint.