Hi, I just pushed up a small change to ox-bibtex (in comtrib), so that it is possible to include options in cite: links. So for example the following link "[[cite:(Chapter 2)foo]]" will be converted to the following LaTeX "\cite[Chapter 2](foo)".
Best, -- Eric Schulte https://cs.unm.edu/~eschulte PGP: 0x614CA05D (see https://u.fsf.org/yw)