Well, it's difficult to say something short and correct without losing generality, so I avoided the issue entirely.

If you don't put the sessions in the database, SQLite can take you quite far (1M pages / day sounds possible) on a read-mostly website.

There's certainly something to be said about using the same database in dev and prod, and preferrably not SQLite for websites that may receive non-negligible traffic or where data integrity matters. I feel that the deployment checklist isn't the right place for this digression. The databases docs seem more appropriate.