Seems the definition of "expert" is rather loose in your neck of the woods. Freezing temp for undiluted antifreeze intended for use in liquid cooled engines is -12C. It's clearly going to be news to you that adding water - up to a certain dilution point - actually lowers the freezing point. I don't even want to consider opening the discussion to boiling points.
And like the RV fluid, there's nothing wrong with windshield fluid in tires. But where you're shortsighted is in valuing
ballast in terms of dollars per gallon.. The real value measurement is dollars per pound. RV antifreeze for the OP cost him a little over 0.41/lb (CDN). My RimGuard cost me less than 0.24/lb (US). That $237 put about 425# in each rear and 75# in each front. You got your WWF for ~0.15/lb. But did you actually confirm the freezing point? Don't for get that summer WWF freezes in the winter
That said, I can't speak to the price of RimGuard in Missouri or Canada. I bought mine in Western Kentucky, less than 50 miles from the MO border..But at least give other folks a little credit for knowing how to to get the most for their money - regardless of where they live
//greg//