...
However, we understand that there may be specific use cases for these types of toast messages in your applications. The Polaris Design System provides good guidance on how to use these notifications in a way that allows for the most accessible and usable experience, while still acknowledging the limitations of this pattern (Toast — Shopify Polaris).
Known Issues
It is difficult to use toast messages that dismiss on their own in a way that still allows us to comply with WCAG 2.2.1 Timing Adjustable. We are looking at potentially making this a configurable option that the user may set as a preference. However, in the meantime, please use a duration of at least 10,000 milliseconds.
...