Envision the current scenario:

• A document has an view-transition MPA opt-in (@view-transition { navigation: auto })
• That document has some render-blocking resources that take a long time
• The user navigates away before the first frame

The current specified behavior is that navigating away would be stalled until rendering is unblocked.
Suggesting instead that until the page is revealed (the first frame is rendered), outbound cross-document view-transitions would be automatically skipped.