You can (theoretically) create a Chord Symbol Region with Shift-Q reg Enter. However, if there is a chord symbol at the rhythmic position where you invoke the popover (which I’m guessing will be a great majority of cases) the popover will be pre-populated with said chord and no amount of deleting it will cause the reg to register.
PS: Some solutions you don't need to tell me about
- Using the Jump Bar, with or without an alias
- Setting a custom keyboard shortcut
- Moving the caret to a slightly different rhythmic position or making a slightly different selection, then dragging the region back into place
- Temporarily deleting the chord, then re-inputting it afterwards
- Copying & pasting regions from elsewhere