2013 ram 1500 cylinder #2 misfire code

Yikes you covered your bases. Maybe plug wires?? Check this out too. https://www.fixdapp.com/blog/p0302

Just going through this with my 09. Since we have determined it's not the plugs or coil my mechanic thinks it's probably the cam and lifters that go bad on so many of these engines

Low ideal

On a mis fire, if you've changed the coil and plugs, and you still have it, it's not good. Do a compression check. I suspect low compression on the coded cylinder. What happens is the valve seats and guides get worn, or don't seat right due carbon causing low compression. When that cylinder fires, it doesn't fire as hard and as fast. A milli second slower. The computer picks it up and you'll get that code. In the old days the guides were made of bronze, now they are aluminum.