"If the previous document, and any HTTP redirects when navigating, pass the timing allow check algorithm, the unloadEventStart attribute MUST return a DOMHighResTimeStamp with a time value equal to the time immediately before the user agent starts the unload event of the previous document."
That language seems too lax, and we should make sure (in language and tests) that all redirects pass the TAO check before exposing unload.
"If the previous document, and any HTTP redirects when navigating, pass the timing allow check algorithm, the unloadEventStart attribute MUST return a DOMHighResTimeStamp with a time value equal to the time immediately before the user agent starts the unload event of the previous document."
That language seems too lax, and we should make sure (in language and tests) that all redirects pass the TAO check before exposing unload.