If the LF inclusive of the YMML passenger are into the 'high 90's' then blocking out those seats when the 'environmental variables' come into the mix is another inference that the route is beyond the aircraft.
Not really. This is far from the only route in the world that has blocked seats to maintain the integrity of the service, and it’s only doing so on a minority of services during a small window of the year to a small number of seats. If the remaining seats are full, (as you can imagine they pretty much would be if the regular loads are in the 90’s), then the aircraft still has an 80% load factor based on its maximum capacity. Well above break even, especially if you consider that Business and Premium are full, and of the freight carried, some of is ‘premium’ in nature, being time critical or benefiting from the lack of an additional stop in warm climates.
True, the yield premium is there only if there is schedule integrity, but if you are asking 20 or so (no, not 45, they aren’t flying 100% full), lower yielding economy pax to head to London via Singapore to ensure this, I hardly see the drama.