Short answer, when it starts to cause problems. There really isn't a service interval on a chain. When you start to have timing codes pop up and things like that, that's when its time. If you keep your oil changed and topped off, chains will last a long time.
I say change around 175k miles. That seems to be about when the chains in K24 engines start to show signs of wear (decrease in performance, some noise possibly). I prefer to do this type of work before a problem occurs.
I’m not 100% sure but I think my chain broke in my 2005 at 192k (it was never diagnosed but I’m reasonably certain that was the issue). My 14 is at 100k and i was wondering the same thing and may wait until 150 or so to change it. I will say that i was getting weird codes like the catalytic converter.