I'm not completely sure whether this is as relevant for racing drones as it is for surveillance/video drones. Racing drones often fly at a 45+ degree angle, so

I'm not completely sure whether this is as relevant for racing drones as it is for surveillance/video drones. Racing drones often fly at a 45+ degree angle, so the thrust is angled more backwards than downwards. Also, one of the benefits of the NASA research is longer flights. But racers often don't fly more than 1-2 minutes, after which they swap batteries. A slightly lighter battery could give the benefit of slightly quicker acceleration though and that's pretty important. Lastly, in the pro leagues, they usually fly the same drone, so there's no need to have the fastest drone.