Currently, the hugo configuration file can only enable or disable the Footnote extention to goldmark. The reson for this is that the allowed properties are hardcoded in hugo. The only option for Footnotes and all other extentions other then Typographer is to enable or disable it.

Idealy, this would be implemented in a way that just passes configuration to goldmark, allowing full access to goldmark configuration. If that is infeasible, simply adding more configurability to the markdown engine would be good.