Thanks to @pmusaraj for some amazing updates & refactor to this component. His refactor solved all of the issues that arise when system is set to dark mode & users want to switch their forum UI to light mode.
We have defaulted to not have the toggle be shown in the header menu. This will show it in the footer of Discourse’s new sidebar.
If you want to display in the header, you can choose to show it in the header menu via theme settings.