This request is from 2019 and a lot has changed since the original post.
* There is a dedicated, global shortcut in the desktop application to create a new task (Cmd E on Mac, Ctrl E on Windows).
* There is also a dedicated shortcut (Cmd J on Mac, Ctrl J on Windows) that will open up the Command Center regardless of what app you are in.
* You can use the Command Center to run any command like "Create New Doc", or quickly jump to any task with a search
These keyboard shortcuts are also customizable (run "Go to Desktop App Settings" to get to desktop settings).
We also expanded what types of shortcuts you can use. Now you can set shortcuts that don't include alphanumeric characters, like "Cmd + Space", for example.
We haven't converged the free-floating Command Center window with the quick-task creation flow, but agree with the posts here that it would be a better experience.
I'm going to close this Canny thread to help focus the discussion on what we can improve next, since the originally requested functionality has mostly been implemented.