Other brands simply do not work as well in the KJ
You will find these 3.7s are very choosy in what works and what doesn't
Just like correct NGK copper spark plugs
MOPAR Oil pressure switch
the list goes on and on and has been found over the years that some things you just have to stick to MOPAR
other brands etc have been tried many times thinking we are all idiots in suggesting certain brands but they find out in short order we are not crazy when suggesting parts that actually work
HOAT is a specific chemical makeup of the coolant. Different vehicle manufacturers spec their vehicles with different types of coolant. They determine what works best for their systems. Chrysler has used HOAT for quite a while now. The issue with mixing these different chemicals is that they can react and coagulate. Gum up water passages and destroy the water pump. That's what happens when you mix the "universal" stuff or many other coolants with HOAT based coolants. I've seen it happen. I use Zerex G05 in my 2011 Dodge Avenger (3.6L) and always used it in my departed Jeeps that required it.
I do know a few people who had their Chrysler vehicle's coolant system completely flushed and then filled with the universal green stuff without problems but the HOAT isn't much more expensive and should still be used.
The universal stuff does not work at all in our KJs
Even when flushing it all out, the universal coolants do not protect the aluminum etc that out motors have as well , if at all
If you go into any " good " parts store they will have HOAT coolant ( Zerex G05 )