I get your point but it's such a niche use case that I can't see it coming up in real world situations. I mean, "never say never", but it's a solution that crea

I get your point but it's such a niche use case that I can't see it coming up in real world situations. I mean, "never say never", but it's a solution that creates as many problems as it solves. I used to build online games that fed off real world events. Eg football managers based on real football matches, games based on horse racing, F1, tour de France, and many others. We needed to change feeds when the match started and ended, but sometimes events are delayed or run into extra time. So we needed a way to change that quickly. We also needed to present different screens at the start and end of the event to the live scoring during the event. This all meant it was easier handling times based cut offs in JavaScript with the live scoring JSON files (which were being fed from S3) using cache control header because it was easier to set an X seconds into he future time out for that than rewriting the S3 tags every few seconds with a new expires header. On paper our use case should be precisely what you described but even we found expires to be unnecessary.