How do we share play raw that don't have a sidecar

How do we work with editors that do not “emit sidecar or other files”, e.g. my GIMP 2.10.34?

Just describe the main steps you have done.

This is the correct answer.

Not as short or as easy as it sounds and certainly less comprehensive than a side-car file.

I think I’ll stick to RawTherapee for ‘Play Raw’ work.

I did a quick test in GIMP 3. Looks like what you are looking for is tacked onto the end of the .xcf file when saved. You would need to mention this to the developers to see if they would implement the change.