Can I run a second instance of Joplin?

I think this question fits with this thread. I would like to use the portable desktop app in general, but be able to add notes via the command line, either

mn "note text here" --file /path/to/file/attachment/here
OR
mn --use-clipboard-contents

If I understand correctly, the databases for the terminal app and portable version (and installed windows desktop version, too) live in separate places, so this would not be possible. Is my understanding correct? Would it be easy to implement the command line addition of notes as I outline above?