Well, if the teflon in a teflon lined heim joint is gone, it is in fact worn out by definition. Shouldn't be a hard concept to grasp. You're supposed to change them when that happens. I don't know what being in the north east has to do with anything, since none of your cars spend any amount of time on the street anyway. And regardless, worn out is worn out anywhere. If that happens in a few thousand miles or tens of thousands of miles, it's still worn out.
"heim" is not a company. Heim joints/rod ends are made by lots of different manufacturers, so, your wild generalizations are irrelevant. None of the heim joints on any of my cars are made by "heim".
And just like a ball joint or a tie rod end, if they're worn to the point that they're making noise, they're junk.
70k street miles on the QA1 heims on my Challenger. 70,000. They don't make noise. If yours do, you're behind on replacing them. This is basic stuff, someone with your experience should know that.