Oh yeah I did observe that but couldn't bother making the distinction. In my head, that's the worst case for a decent portion of users (2-5% depending on where your users predominantly live and other demographics) so I consider that to be a 24 hr outage.
Your approach definitely sounds sane, would encourage others to do the same rather than following the article from the get go.
In practice for our app we rolled out with 600 to make sure things were working. And now we run at 28800 (6h) (but 2h on Chrome)