Bug: Theme does not switch while active
If KeepingYouAwake is active and the OS is set to automatically switch between light and dark mode, the OS does not switch the theme while active KeepingYouAwake is active.
I don't know if this is a KeepingYouAwake bug or a [caffeinate] bug - nonetheless probably worth to document.
That's indeed a tricky one. I've noticed that myself over the years too. There is sadly no public API to allow/perform this dark mode/light mode change. It feels like macOS prefers doing these theme changes when you return from standby or when you close and open the lid again. I will keep this issue open and continue doing some research. Maybe there are indirect ways of handling this.
Thank you for your feedback!