Just recently bailed on Chrysler/Mopar because they abruptly disconnected my vehicle (PHEV).
But still, almost daily for over two years now, owners are coming in complaining about blown head gaskets on the Pacificas. I was searching to show that this issue is not Pacifica-specific and an issue with 3.6 in general. This thread came up in the search. I posted it here: Advice on Spark Plug/ Engine Misfire | 2017+ Chrysler Pacifica Minivan Forums
My conclusion is that nothing can be done to prevent these issues in 3.6. You either get a good one or a defective one. Thought it might help give fuel to your cause, sharing the recorded list of failures over in the Pacifica camp.
Mine just went out. 2020 gladiator with 65k miles. Didn't even bother with a repair and just bought a new engine from factory with 3 year warranty. Feels so wrong to have to spend this much money on a truck with such little miles. Ill be way more meticulous with maintenance moving forward.