Board Thread:New Features/@comment-2240397-20161117122547/@comment-24473195-20161117124040

Hmm, lots of posts today.

The master and slave theme approach works. By why not simply save yourselves some hassle and add something like "themes":  {My Infobox|themevar=theme1;theme2;theme3;}} 

As long as one uses a delimiter that is invalid in a css class name it should work just fine...

Currently it doesn't seem likely that making your suggested change will have any negative consequences, in fact, it will allow users to remove some hacks to add this functionality.