If I understand you correctly, I would have to duplicate the file, flatten it. save it, and then open using the "open as smart object" as a raw file. This did work but when the file was edited and then saved it save as 8bit file, instead of the 16 bit file I started with. Idid not see a place to keep it a 16 Bit file.
Is this the correct procedure? Is there a way to retain the 16 bit file?