Sorry if I wasn't being clear.
The question was should we allow duplicate keyboard shortcuts for actions if for example, one of them is only allowed in note list, and the other one is only allowed in note body.
Both of those actions are presented as one action: "Select all" to the user. There's only one shortcut associated with it. This is about two different actions.
If the user is focused on note body, all keyboard shortcuts are enabled and usable as per my understanding. This makes having the same keyboard shortcut for any two or more distinct actions impossible in any other case.
Moreover, I think it's better to only allow an unique keyboard shortcut for each action as a user experience measure. But that's just my opinion.
Source was actually just an indicator for the user to see if they've changed the shortcut or it's still the default. It was just an alternative suggestion. For example, it'd say "Default" if user hasn't changed it, and "User" if he/she has. I was suggesting it as an alternate to just show commands whose shortcuts have been changed in italics and others in regular text.
My understanding about shortcut context was, since they're already handled well with menu items ("Select all" meaning two different things, menu items automatically disabled when unavailable, etc.) we wouldn't need to pay special attention to that area in the keyboard shortcut editor.