BTW, the use of sand and water to create accelerated wear is consistent with other engineering testing methods. In testing plastic parts to failure, it is often the case that the part will last a really long time making the test impractical. What is done is to raise the temperature of the testing. Every 10°C or so doubles the rate of many chemical and some physical processes. In any case, we can use "time-temperature superposition" to be able to test the part at high temperature in a reasonable amount of time to predict what will happen at lower service temperatures.
That said, the accelerated wear in this test may not be a practical indicator of chain life if folks use a different lubricant, and/or clean their chains often, and/or don't ride in dirty or gritty or wet conditions. I'm a fair-weather road bike rider. Rarely do I ride on dusty roads. We read above that folks get (sometimes) 1000s of hours of life from their chains, not 160. If I was a NYC courier riding in all conditions with lots of road grit, and didn't to the maintenance on my company bike, the test might be very applicable. For me, not so much.
Frictional differences between chains are pretty small - about 1-2 watts, according the test cited below. Still, Shimano and Campy seemed to be signficantly (0.5 to 2 W) lower in friction.
https://cyclingtips.com/2019/12/the-...ncy-comparison