Be sure to check for ... "Meets Ford Specification ####..." to be sure it is compatible. Some types of coolant turn to jello if you mix them with something else. Read the manual for the coolant specification. Some anitfreeze make it a little easy by saying they are compatible with Gold fluid. Probably OK but I haven't read every bottle out there, so I make sure about the spec.
I do not know much about the Ford Gold fluid other than I just buy a jug that meets the appropriate spec. I add distilled or DI water(we make the stuff at the factory.
The main reason for the premix is like one of the guys said, water costs a lot less than coolant and they get to sell more bottles of premix than 100%. Minor part is convenience.
manly men use real coolant and change their own oil.
Jim Henderson