Agree. Why take a several thousand $ gamble trying to save a few $? You MIGHT be ok with certain brands of aftermarket stuff that says "compatible" to mix & match, but maybe NOT. If you do gamble, be sure to completely flush all remnants of stuff currently in there, then start fresh with the aftermarket & distilled water. Especially true for those who have bought a used vehicle and are not sure what the previous owner put in there, or if it was ever changed.I have an unfounded uneasiness of using alternative OAT coolants that contains 2EHA. The MOPAR coolant does not contain it while most OAT equivalent coolants do. 2EHA is the plasticizer that allegedly contributed to the catastrophic GM engine problems years ago. Modern engines are supposed to have gaskets, sealants, and plastic parts that are 2EHA tolerant.
I admit that it is probably an unfounded fear based on decades old bad experiences. We all have biases that are tough to let go. On the other hand, I have no problem using "approved for SP4-M" non licensed transmission fluid. Go figure. The MOPAR coolant cost only about 30% more than generic products. SP4-M is about 300 - 400% more than "equivalent" products.