I have used it before years ago, its $$$$$ **** but works great.
Had it in a daily driver, minimal thermal expansion. Then they advised to get a 0psi cap or just cut the pressure portion from your cap assembly.
It actually worked so well in the vehicle that during the winter the radiator had to be restricted to allow the engine to reach proper operating temp. :****:
This was back when it was only NPG+ and $75 a gallon.
Will i run it in my buggy??? NO, straight distilled water and redline water wetter, then a bit of antifreeze during the winter is all i plan to do this time around.