I suspect you, Valkyrie, are speaking about the requirement for new listed permanents (not DIYs)?
John Ward is not a computer, where everything is a 1 or a 0. If you have an idea for a permanent that would require a control in a town where the only options are open in (reasonable) hours, then put your idea forward to him. Based on my past dealings, I suspect you'll get a sympathetic hearing if it is a route in a part of the country not well served at the moment.
From my own rider/organiser perspective, a clear and up to date list of when controls are open seems entirely sensible; the only thought that struck me was the ability to guarantee the control will remain open (and how frequently would you check) and if not, are there alternatives. Not knowing the details of the route, I'd also be looking (from a rider perspective) that the window of opportunity for riding has some flexibility on where you can start the ride and the time (both of day and of year), but that's personal preference.
That all said, not every good long distance route is suitable for audax. Proof of control is a fundamental requirement and the 24 hour rule would seem to be a sensible starting point, unless an alternative presents itself.