Last year I purchase a 2019 Ram 1500 with the V6 engine, with 40K miles. I avoided the V8 for lots of reasons, but choose the V6 because I have had two of these engines in other vehicles (2011 Dodge Durango & 2014 Town and Country) both went over 200k miles without any significant engine issues. Like you, I did all the scheduled maintenance and much of them myself. What I have overserved with my Ram truck is that the engine does run hotter than my other two vehicles (never exceeded 212F). This past summer, I did experience 225F with my Ram and wondered about replacing the thermostat to avoid any potential issues like you are having. Another observation is that the analog temperature gauge never really changed between 190F to 225F which is what I was reading on the digital gauge. Wonder if you experienced something similar?
Some advice: I have read all the chain of messages and agree with many of the comments. However, I would find a local mechanic that you or a family member trusts. Let them do an analysis and if it needs a head gasket, let them do it. If your head is warped, then buy another head. It will still be a lot cheaper than the $13K the dealer quoted you. Keep in the mind Chrysler FCA has a lot of inventory and they want your to trade it in and sell you a new truck. My last piece of advice is to replace both head gaskets at the same time. The likelihood is if the increased temp cause one gasket to leak the other one is not far behind. Your paying for the labor already, a second gasket and labor will be cheaper today while they are in there, rather than going back a second time in the future.
Thank you for sharing your experience and your service to our country. Let me know how it goes.