configuration in plugin definition

[Announcement]

readme.md

postcss([
  stylefmt
])

question

this doesn't error, but doesn't seem to work.
my question is, why does this module not accept inline configuration like other modules, and can we add it; may I just be doing something wrong?

postcss([
  stylefmt({'block-opening-brace-newline-before': 'always'})
])