Unfortunately I've no experience with Handlebars, so I don't really know how the extension needs to be structured to make sure that the utility functions are available in the proper scope.

If the issue is with the Handlebars-precompiled output, can't you use `build()` from `bin/messageformat.js`? That should get you working output, with a single definable global, and the utility functions as local variables within that. Or is the problem something else entirely?