I too am still trying to wrap my head around the physics of that. I still don’t see you how you can run a diesel too lean. Fuel is control for everything, from desired RPM to full power. I don’t see how just by simply adding air with no more fuel will make it over heat. There are thousands of pickups with larger drop in turbos and the benefit is lower EGTS (more air to burn whatever left over fuel there is). None of them experience over heating. Granted, i this is going from NA to turbo, but still shouldn’t matter. Working against the governor as previously stated I can see that happening, but not just from increased air flow. There are even turbo kits for the old 7.3 IDI available for the non turbo models that you could bolt on with no fuel added, and none of those trucks had issues over heating or running hot. The benefit is reduced exhaust gas temperatures
If you have any literature backing up running a diesel too lean I’d love to see it.