Make Notifications more accessible - eg. when display is on: a 2nd double side-tap could navigate to Notifications directly.
I use the device a lot for checking notifications I missed while walking etc, and getting to the notifications on the device is not too easy.
I'd suggest to add device menu shortcut feature. Like:
set one Sub-Menu point as shortcut on the Phone app, and make it easy to access, e.g.:
--> make it accessible with a second double tap on device-side when screen is on.
--> add that menu point to the first level of menu instead the second level menu going through the finicky Sub-menu
The double tap solution would make it a killer-feature of the devices.