Not sure if this was really obvious to other people, but here goes…
When you get an activity notification, e.g. “You closed your stand ring” or “You’re so close, take a 15-minute walk”, have a look at the little activity ring icon at the top of the notification. It should reflect the current state of your rings. So without even clicking on the notification or going into the activity app, you can see how close to being closed each ring is.
Blew my mind when I noticed this. Love these little bits of attention to detail.
Hope other people find this useful!