yes, +1 for Keep integration as well.
Currently, I'm using google keep to type in my note cards for each article. Keep allows quick search, tagging and colour-coding. Usually, i copy the citations as title for my note cards. The body of the note cards would be "text" from metapdf and my comments as text too into Google Keep.
But the workflow requires me to switch back and forth between PP and Keep.
I sort of avoid the Notes icon in PP's interface, as I realised there's no off-line access and no easy way for mass-export. Or is there?