save a Ghost Curve (Snapshot) within the .blend file

Ghost Curves are an incredibly useful tool. You can create a beautiful and very precise Bezier curve by referencing a Ghost Curve. But how to save the snapshot to the .blend file?

Example: I've used Clean Keyframes. After some time, I recreated half of the curve. Then I need to pause the process and return to it later. After closing Blender, the Ghost Curve disappears. How can I preserve it?

I bet if regular reference images, empty and planes were deleted when saving a .blend, you would also be concerned