Copy/Paste to other project and don't lazily "hard decline", figure it out.
You should be able to copy layers, then open a new project and paste those layers in. There are all sorts of solutions including packing a temp smart material into the clipboard.
This was suggested before with a lazy response of "This causes all sorts of issues" and I'm calling BS on that. Figure it out. You now have all of Adobe's resources to call on. Do so.