I think the question to be asked here is: "It leaks ... where?"
The most obvious culprit would be a bad radiator cap. Either perform a pressure test of the cap and the cooling system or even just start by looking for cracks around the sealing surface of the cap, and inspect the rubber gasket as well.
Having a pressurized cooling system is likely MORE important than attempting to lower the coolant temperature. A properly pressurized cooling system with the correct 50/50 mix of antifreeze and water will have a boiling point in the range of 250° F.
If it's leaking elsewhere, lowering the temp or the pressure in order to stave off the leak is a "band-aid" fix that isn't going to last, IMO.