Are you on iPhone (iOS,) iPadOS, or macOS?
Just did a brief test:
⌘ + ⌥ + ⇧, ⇩
On macOS:
- When Inbox is in focus, navigates between the beginning and end of the list.
- In the editor and when the Actions List is in focus, macOS gives me the “nope” sound.
On iOS (iPhone 12 PM):
I was not able to get the shortcut to respond whatsoever.