Speaking of battery, did some more reading on the Apple Watch stuff, and it turns out that rate limiting won't actually be an issue unless updates are needed really, really, really frequently. The issue is more of battery life on the watch. For that reason, Apple asks that you try not to update complications within minutes, and give as much future data as you can muster, which is a massive problem for something like what we're trying to do. The general approach for applications like nightscouter that need data often and can't anticipate it is to load off most of the work onto the iOS App with watch connectivity. I'm working on that rn.