I agree the notification light would be great, but does the Nokia 6 not have a "glance screen"?
I didn't realise that the 6 didn't have Glance. Not all screens support it - the Lumia 930 disappointed people when they discovered it didn't have Glance functionality, it was an own-goal for Nokia (just like the 950 not having super-sensitive touch).
If the screens support it then HMD should provide rich functionality - remember what Nokia did back in the day with Sleeping Screen for Symbian?
We need this feature