I'm hoping beyond hope that whatever is causing the overheating on the 15 is the same thing causing battery drain on my iPhone Pro Max 13. I've been on iOS 17 for about 2 weeks now, so any of the reindexing, etc. should all be done. My phone goes through its battery much, much faster now. Before iOS 17 I had never had an instance of running low on this iPhone, even on days with very heavy usage. Now, even with normal usage, I end up on low power mode by the early evening. I should have known not to upgrade to a new iOS version until it had been vetted by the public. This is not my first time to be burned by Apple.