This update adds a lot of new pie menus, while fixing any issues reported in the last 6 months. Thank you to everyone who submitted suggestions, bug reports, pull requests. Feedback welcome.

New Pie Menus

• Curve Edit Mode: Curve Delete Pie (X + Drag) - Same 3 options, but grayed out when they wouldn't do anything.

• Animation Editors: Keyframing Pies:
  • R -> Keyframe Type pie (Dopesheet only!)
  • V -> Handle Type pie
  • T -> Interpolation Mode pie
  • Shift+E -> Extrapolation Mode pie

• Object/Pose Modes: Copy Pie (Ctrl + C)
  • Inspired by Copy Attributes add-on, which has gone unmaintained for many years (I was the last one to touch its cold corpse years ago)
  • Mesh data copying functions are omitted for now. If anyone wants these, please say so.
  • Copy selected modifiers/constraints/custom properties between objects and bones, along with their drivers, geonode inputs, physics and baking properties.
  • Copy objects or pose to clipboard.
  • Copy collection assignments, viewport display settings, and various groups of properties.
• Mesh Edit Mode: Mesh Edge Pie (Shift + E + Drag)
• Object/Mesh(Vert/Edge/Face)/Pose/Armature Edit modes: Select Similar Pie (Shift + G + Drag)

Improvements

• You can now hold Shift when executing "Delete from File" (X pie) to get a pop-up displaying users of the datablocks you are about to delete.
• "Delete" and "Unlink" buttons (X pie) now work for Library Override datablocks; They will delete or unlink the whole override hierarchy.
• Add Depth of Field toggle and F-Stop slider to Camera Pie (Alt+C)
• Changes to Apply Transforms (Ctrl+A) pie:
  • "Make Instances Real" on the bottom left replaced with "Apply Modifiers & Shape Keys", at user request.
  • "Clear Transforms" drop-down menu in the bottom right expanded with more options and re-labelled to simply "More..."

Fixes

• Fix #163: Use new operators for loop and ring selection in 5.1 onwards contributed by @Dvorakir, thank you.
• Fix pie_menu_on_drag operator appearing in "Repeat History" contributed by @Bastian, thank you.
• Fix #167: "Unlink From Scene" in Outliner not doing what it says

Also updated documentation with some pie menus that were missing, as well as all the new and modified ones.