@edward & @sdenardi - yes, this is currently correct. #zmmtg-root appends into the body on import, and needs to be hidden on load. Hiding it in this way should not influence .init() or .join() from overlaying the page when the meeting starts.
Considerations for future readers: If you’re loading another root element (like in React), you’ll need to manage/manipulate the DOM outside of the app. And make sure to include required css files in index.html, not within the app.
We’re working on improving support/usage for module importing and SPAs.