Where to get aftermarket Mazda FL22 coolant?

My car's manual says to only use FL22 coolant which Mazda wants around $40/L (it's only available premixed) so I'm looking for a cheaper solution.

As far as I can tell, FL22 is the same specification as Ford WSS-M97B55-A: Phosphated Organic Acid (P-OAT) free of silicates and borates.

Found this: https://www.penriteoil.com.au/forums/topic/14/Coolant%20&%20...

But the Green is phosphate free with silicates, while the Blue contains neither phosphates or silicates. This seems to be the case with all of the aftermarket coolants in Australia from Valvoline, Castrol, Nulon or Penrite, even though their product selectors claim at least one of their products are compatible.

Even this product: http://www.ravenol.com.au/product.php?code=1410122 claims it meets FL22 specifications but says it's phosphate free? What am I missing?

Please help, surely there has to be an alternative to a $300 coolant change…