As confused as this Anti-Freeze/Coolant subject has made me over the last decade or so, I have recently started thinking about my personal >40 years of shade tree experience and the years that I worked with my dad, who owned his own garage('55-'79).
I have never had any particular head gasket, intake manifold gasket, T-Stat, water pump or heater core/radiator problems with any vehicle that I have ever owned due to using the wrong coolant with the exception of vehicles that were *"known"* for having these particular issues...GM V6's(2.8, 3.1, 3.4) and Mopar 4 cyl(2.2/2.5) and the proper coolant was coincitently was being used at that time.
I have used any coolant in every vehicle that I have ever owned, miltipal times and many hundred K's of miles with vehicle into their teens. Engines with all cast iron, cast iron/aluminum mix and all aluminum.
I know that we as consumers want the best for our vehicles and too, there will always be that(isolated case(s) cooling system failures from any MFG that will blow a gasket or have a particular cooling system issue, even a system not known for having problems.
But, in over 40 years of my own experience with(WITH) KEY WORDS...Properly Maintained Cooling Systems, I have had no real issues!...Again, except with vehicles that are/were known in the industry for having these problems. And also, YES! I have replaced items that have outlived their life expectancy such as water pump, T-stats or ratiators(that were rusty from winter salt exposure).
So, with all of the concerns of todays Anti-Freeze/Coolants and todays cooling systems, there may certainly be the need for specific coolants for specific systems but, I beleive a properly maintained system will give the owner a long service life without issues...Properly Maintained!