Thanks for the reply. I think I need to go back and do some proper testing to check what I think I’m seeing. I am pretty sure Aperture respected the flag/embedded JPEG through the import process.
I don’t use Photos for “proper” photographic processing, more as a CMS with some basic stuff attached. Even your plugin doesn’t make Photos a nice place to be for me. The good photography was always Aperture, and now RAW Power.