[tag:status-completed]I asked this as a question, but apparently the convention is to report bugs/feature requests in the announcement thread. 
It appears, that the [MathJax extension mhchem][1] is currently not enabled in the StackPrinter app. This is rather inconvenient for most of the chemistry.se questions and answers. It would therefore be nice if this feature could be enabled for the StackPrinter app.

Example:  
Please consider the [sandbox on meta.chemistry.se][2] and its [printed version][3] (also see the screenshot below). You can see in the first equation of my post the red `\ce`. I enabled the mhchem package manually via `\require{mhchem]` after that and the same command renders now. 

![printed result][4]


  [1]: http://docs.mathjax.org/en/latest/tex.html#mhchem
  [2]: https://chemistry.meta.stackexchange.com/a/388/4945
  [3]: http://www.stackprinter.com/export?format=HTML&service=meta.chemistry.stackexchange&printer=false&question=111
  [4]: https://i.sstatic.net/Titev.png