Hey @chris.w,
Thank you for reaching out to the Zoom Developer Forum. When it comes to the Client View, we don’t currently support customizing the UI or changes with custom CSS/JS.
When it comes to the Component View, we plan to support UI changes in the near future.
In the meantime, I recommend referencing our Sample Web App when customizing your application to ensure no issues are introduced.
I hope that helps! Let me know if you have any questions.
Thanks,
Max