Junk Yard · Troubleshooting the Junk Yard
Why are the Junk Yard settings greyed out?
Short answer: The Junk Yard is turned off on this Mac. Switch on Enable Junk Yard on this Mac in Settings → Junk Yard and the other settings become available.
Because the Junk Yard is switched off on this Mac. Every setting below Enable Junk Yard on this Mac is disabled until that toggle is on. Turn it on in Settings → Junk Yard, and the rest of the options — capturing, shortcuts, curtain and storage — become available.