From a time long ago we had a global options object to set the compiler options, eg which features would be enabled.
When we got modules to work we passed the global as a module property.
As we got to more complex usage scenarios we started having functions that took options as arguments.
Well, the combination wasn't easy to understand so now we removed the global option and the module-property option, leaving only options passed by argument.
Let me know if something is no longer possible. I'm guessing that browsers that load traceur and use our script tag processing may have an issue but rather than guess I'd like to see a specific report.