There should be no "PAR FOR THE COURSE" for your car. Something is wrong. They just haven't figured it out yet. A couple of obscure thoughts come to mind. I still wouldn't entirely rule out the possibility of a oil starved lifter. There could possibly be a damaged or loose rocker shaft cap (not likely, but possible) at that end of the engine. Also, I have seen one case of a valve seat insert not being fully seated in the head causing the valve clearance on that valve to be excessive. Lifter was able to make up the difference, but it took a little longer than usual. This was a Mitsubishi inline 4 cyl. Something is causing this noise. If it were par for the course, why haven't the other 23 valves, etc. heard about it??
2000 Dodge Grand Caravan SE
No matter what you fix, there will always be something else to fix..
"Warranty" is just another way of postponing the inevitable.