[switch]: Should author defined content be allowed on tracks or thumb?

I'm working on the switch proposal pull request. @scottaohara raised multiple concerns with author defined content inside the different parts of the proposed <switch> element.

Question

Should authors be able to add text content to either the track or the thumb elements?

Research

About a third of analyzed Design Systems use this feature (Design System Analysis section in the pull request).

• 30% display content on the track
• 18% display content on the thumb

Example: https://ant.design/components/switch

Accessibility concerns

• Content mapping will be difficult since it's a new concept
• The switch is already described by its label and content should be ignored

Relevant comment: https://github.com/openui/open-ui/pull/785#discussion_r1396420527

Layout issues

Custom content can have various layout issues.

• The content on both sides cannot be wider than the thumb. Otherwise, the thumb is no longer capable of hiding the content of the inactive track content.
• It’s unclear how to style the track and slider if the track content can be of arbitrary length

Live example on codepen using ant design system

Possible solutions

1. Allow for author defined text/content and find solutions to the above issues
2. Don't allow for author defined text and risk not adressing all existing use cases
3. Only allow decorative images or svg content, which covers most use cases and avoids the above issues mostly
4. ...?

Start with the switch proposal pull request #785, especially its Design System Analysis section and the linked accessibility discussion. Compare the track and thumb content use cases, including the Ant Design example and CodePen, then resolve whether author-defined content should be allowed. Done means the proposal has a decided treatment for text, decorative content, accessibility mapping, and layout concerns.