[aerohead]

I vote: 'leave it alone!'
When it's open, it's an industry leader in hydrodynamic efficiency.
The entire cooling system design is predicated upon the thermostat's architecture exactly as it is, transporting a miniscule amount of coolant at cold-start, and turbulent 'blending' of the solution throughout the cooling system, to produce an 'average' coolant temperature as 'seen' by the ECU's sensor suite during open-loop operation.