Airlines (executives, I mean) are using that rule of the less than 6 hours, VMC, two runways, etc... to eliminate the alternate fuel.
Still, when you do that you need to uplift 15 minutes of Additional fuel.
Some airlines even use that during replanning (typically redistpatch in flight) so that once in flight and withinless than 6 hours to arrive they can eliminate the alternate fuel requirement. I assume they add the 15 min...