This is exactly what I was hoping to suggest. I intend to run ads through Twitches Ad Manager, but I also want to give my viewers a warning that a 3-minute ad is approaching.
Currently my only way to do that is to keep the dashboard up (using precious computer resources), watching the dashboard when I should be engaging with my viewers and the game we're playing and hitting a button to enable an on-screen and in-chat notice about the upcoming ad.
TLDR; it's just one extra thing I have to worry about to be the fairest I can be to my audience. API access to the ad warning and snooze function would let me use your tool in the most ease-of-mind kind of way.

I came here for eactly this. Being able to bring up a timer widget for when ads are over. 1 minute warning. All those kinds of things would be invaluable.

Twitch Dashboard SUCKS and most streamers don't use it, as there are tons of better alternatives, even embedded into the streaming software (no, we don't use twitch streaming software either, because it's just bad) or the tons of chatbots available. We don't ask you to develop would software, just give us the chance to access the information without forcing it to use your half-baked tools

API for this would be super handy, so that a streamer could be able to send a chat notification automatically through chatbot or other means that an advert is starting soon