Hi, This is a plea to allow passing arbitrary parameters to pandoc, and on a per file/frontmatter basis too. The original github issue that led to making pandoc an external helper (here) touches on the question of arbitrary arguments, and that point was rejected. Somewhere else someone also raised a security issue, due to the potential of running arbitrary code. I want to ask again the feature of passing arbitrary arguments, because current pandoc is like the neglected third child in the helpe...