This is not about citation style, but about reference types. Paperpile covers many main one: journal, book, chapter, presentation, etc. — but some key ones are missing. For example:
Well, actually, that’s the only one I have reached for and not found.
It would be cool to have all of them available in PP, even if all those not currently present were relegated to an obscure box. I imagine this may be a low priority but thought to throw it out there.