I also found that a binary notification is all I needed. I just want to know if everything is running OK or if there are delays. So I built this a few years ago: https://unop.uk/train-disruption-indicator-with-a-blinky-tap...
There is a ~mirror at https://unop.uk/tube/ in case CloudFlare go down. Although as I discovered recently, this doesn't help as the API runs on them too! There's another API I could use as a backup but it's not as good.
For the curious: https://reactube.com/