It's also there for cold weather heating, getting the engine up to temp quicker for emission regulation.
My friend came up with an idea and it works brilliant, he skipped the coolant heater and made a simple heater with the EGR valve instead.
He turned the EGR valve 180 degrees, pointing backwards. Made an exhaust/coolant heat exchanger, the gases goes through the exhanger and then back into the downpipe. It's easy fabricated in stainless. Then, he shut off the valve when the coolant is warm enough.
Reuse of the exhaust, that already is warm (you did pay for it!) and the car is super warm in a minute even when the snow is deep outside.