So they are going to put just 40 pax in an aircraft of a different type and feel they can get results from this.
What about the impact on those pinioned in Economy window seats by those alongside who are asleep ? What about the capacity of the toilets with a full pax load ? Will they serve minimalist Economy catering to those at the back, or will everyone get something better ? Will you be told "your choice" has run out and only the veggie option is left now ? And 1,001 other issues which will not be replicated. Regarding the crew, these are apparently new aircraft delivery flights, so one way. Surely the crews should do both ways, with the proposed layover time.
The Great circle route takes you across the South China Sea - right through the middle of China, up the top of Kazakhstan and down, across Western Russia then down through Estonia and the Baltic to Britain...
I recall the nonstop LHR-SYD 747-400 from 30 years ago (gosh, really was that long ago) heading right overhead me as it departed London. If I recall correctly, it routed the "conventional" way, over The Gulf and the Indian Ocean. When you are going pretty much one side of the world to the other (I know it's not quite that) it doesn't matter hugely which way you point, and the winds become more significant. The Singapore-New York A350 sometimes routes over the Pacific, sometimes it comes overhead London.