To customise feeds for a single property panel within the email editor*, start by navigating to the email editor, and select a property panel to make it active.

* If you are an Admin, this will affect this panel for all users that you delegate the email to.

From here:

• If not already enabled, select the feed toggle to move it to Dynamic
• Select Define Properties
  
• Within the Define Properties menu, select the Feeds tab.
• Within the Feeds tab, you'll see that the Use My Account Settings toggle is ON, and your feed selections are viewable, but not editable.
  
• Click the Use My Account Settings toggle to the OFF position, so that the feeds are editable.
  
• Tick or un-tick feeds to use in this panel.
• Click Continue to save changes.

As an Admin, you can also customise feeds by individual User.