@dam00r Are you saying that you caught something that 646 professionally trained engineers, most with at least a masters, and a big portion of which have PhDs, missed something you found?
The McLaren, and Red Bull, are just about the two most different cars on the grid in terms of aerodynamic concepts, as very much evidenced in their cars. U-pods vs shrink-wrapped side pods, under-nose vanes vs snowplough. Even the way that the Red Bull has employed extraction augmenters for their diffuser is quite different to the McLaren.
You’ll find that it’s not a single part, or even a collection of parts where the Red Bull is stronger than the McLaren. The car in itself is just a bit better in every inch of it, rather than being better somewhere.
The squarer shoulders, if anything, mean a bit more drag. It would have negligible effect on cornering