Darktable 3.0 Exif on export

Thank you very much. But when I want to remove the serial number of camera and/or lens, how do I do this when the tag is missing in the utility?

And when only the variables supported from the snapshot you sent, why is $(EXIF_FOCAL_LENGTH) working? The variable is not in the list.

Will there come more variables with next updates of darktable?

Regards,
Marcus