Exactly the same workflow you describe. The only difference is that I render the image with a queue plugin with autosave final image.
Then I save the cxr file, close Cinema4D. Turn off the computer. Turn on the PC, open C4D, open the file I want to resume the render, open the VFB, click on render resume file, select the cxr file, but nothing.
Update... Works, but before your third point, I've to start a new render, at least two passes, stop it and then press "resume file" and select the CXR file. Then it works. A little bit complex but works
Thanks