I think the issue warrants having a discussion on how the approaches impact usability before embarking on a fix - the approaches listed in the linked ticket are possibilities but all of them have implications.
The fix has a region with 'assertive" status means that any toast will get announced and potentially interrupt what the user is doing, making it intrusive at times. Actions like 'Saving the sketch' may not be considered that urgent enough to warrant an intrusive alert.
Similarly, increasing the duration although a decent option may still be inadequate from a UX perspective as the notification may outlast the action for too long. Thinking about the use cases and the implications is important from an accessibility standpoint. @raclim

I have successfully changed the ARIA live region to "polite," ensuring that the screen reader will finish the current speech before announcing the toast message. However, the original duration for "Sketch Saved" was only 3-4 seconds, making it difficult for the screen reader to announce it in time. By the time the screen reader finishes the current speech, the "Sketch Saved" message will have already disappeared. Therefore, I believe increasing the duration is a necessary update to effectively resolve this issue. @raclim @dsaw

Thanks for taking a shot at this!

I think I'm not entirely sure yet if this might be the approach we want to go with, and agree with @dsaw that we might want to discuss several options for implementing this first (for example, where are all the places in the editor that the toast is called, how long should the toast be up for, etc), and potentially look into how other platforms might be integrating something similar.

Since this might take a bit more research first, I think it might be best to take a step back before implementing this. I'm going to close this for now—I think there were some good points raised within this PR though, so I think this discussion should be continued within the linked issue!