Yeah but again, Nanite is not eating your framerate.
Lumen and Raytracing is.
If you disable both, and just use Nanite, you will have the same performance as without Nanite ±1ms.
HWRT is turned off in your second Build, you can see no Raytracing Scene in the profiler.
You are totally right that your second scene is more optimized, but your reasoning is wrong. Nanite is not tanking your framerate…