Another thought, is the situation the same with seasons (i.e. up to 2359) too?
I cannot find any mention of the "0429 next day treatment" being applied to season tickets of any length (could be a problem for a commuter in London returning home late after a few jars maybe?).
Though that being enforced would rely on tickets being checked that late at night which is rare (actually it's just as rare during the day on the (peak) trains I get but that's another issue)