300-500 status codes and fallback pages

This is sort of related to the redirect issue discussed before, but have
the status codes that trigger fallback pages been discussed for future
versions of the appcache? I've found the current approach of having 300-500
http status codes trigger the fallback pages to be counter-intuitive, and
it messes up the use case of having a site that's not cached, but still
takes advantage of using fallback pages if the server is offline (which is
currently achievable with iframes).

The individual here has the same issue as me:

http://comments.gmane.org/gmane.org.w3c.whatwg.help/960

I'm not sure if I'm missing something, but I think it'd be useful if
fallback pages could be configured via settings to not occur for 300-500
status messages.

best,

- Pat