There's a huge gotcha: _.map, _.forech, ... can iterate over objects (often used as associative arrays) - Native map can't. At some point you'll need lodash and co again - at least for convinience.
Object.keys() is rather well supported these days though.
for (var key of Object.keys(imps)) { }
I figured that would work with babel-2015 and it did work on Chrome and Safari but on Firefox visitors were getting:
Symbol.Iterator undefined
You need http://babeljs.io/docs/plugins/transform-es2015-for-of/ as well.
So there is much less risk in using _.each(imps, (value, key) => and not having to discover what you don't know.
I also added Firefox to the unit tests after that.