Mobile Apps for Desktop pages

This is in reference to 694 Reflow.
"clarify that a mechanism needs to be available for a user to go to mobile
view from desktop"

I think a functionality requirement needs to be a constraint on mobile
substitutes. My only question should it be full functional or should we
allow some slip? How do we define how much slip is enough?

Consider the mobile versions of mail clients. On a browser, they frequently
require the whole browser to run in mobile format. In that mode many
perfectly good web pages don't work. Now consider reacting to email when
you must use a tab of a page that doesn't work in the simulated mobile
version. Processing mail may require bouncing to other tabs but the mobile
simulation won't let that happen.

Is it reasonable to require a user to bounce back and forth from desktop to
mobile mode and back repeatedly just to read say mail.

Wayne

Wayne