[Retric]

200F is only 93C which is below the boiling point. This is very much by design.

Yes, the coolant loop is designed to be operated under pressure, however being able to drive with a coolant leak under sub optimal conditions is very important.

Further, engines are designed to operate at unusually high external temperatures as temperatures up to 134f / 56.7°C have been recorded, though not nessisarily with a leak. Note, road surfaces can be significantly above ambient temperatures.

[sudojudo]

No cars, in the real world, are driving around with significant coolant leaks. End of story. Talk to any repair shop.

That's the crux of my argument. There is no scenario where one can continue to drive a car with a coolant leak. This kills the engine.

Our discussion feels like a mechanic arguing with an engineer. Probably because that's exactly what's happening.