Possible to choose Screenshot output method with Keyboard Shortcut? The revised Screenshot utility in Mojave brings the handy option of choosing if the resulting Screenshot should be copied to the clipboard or saved as a file, or saved to email, etc.

However this requires that I first press Cmd+Shift+5 to bring up the options, then select my desired option using the pointer. I find myself often needing to switch between saving to a file and saving to the clipboard and wondering if there is a way to do this by a keyboard command or modifier. 

For example it would be great if I could use Cmd+Shift+4 to capture a selection, but modify the command to save-to-clipboard or save-to-file.

Grateful for any suggestions.
It's already there…

System Prefs > Keyboard > Shortcuts > Screenshots

By default
 Cmd ⌘   Shift ⇧   4  will save as a file
 Cmd ⌘   Opt ⌥    Shift ⇧   4  will save to clipboard.