Suspense fallback flicker when async component resolves instantly

Goal

Determine how Vue 3’s <Suspense> handles the fallback slot when an async child resolves in less than a single tick. The observed behavior is a brief flash of the fallback before the component is rendered, which can degrade UI perceived stability.

Constraints

• Vue 3.3+ introduces a timeout prop on <Suspense>, but its effect on rapid resolutions is undocumented.
• Behavior may vary between 3.3.x and 3.4.x releases.
• The flicker is subtle and may differ across browsers and devices.

Unresolved Questions

1. Is there a documented threshold or rule that suppresses the fallback if the async component resolves before the next tick?
2. How does the timeout prop interact with fast resolutions—does it delay the fallback or the async component?
3. What is the recommended strategy for production applications to avoid perceived flicker when using <Suspense>?