I don't think you would need to polyfill Map: http://kangax.github.io/compat-table/es6/#test-Map http://kangax.github.io/compat-table/es6/#test-Map or Set: ht

I don't think you would need to polyfill Map: http://kangax.github.io/compat-table/es6/#test-Map http://kangax.github.io/compat-table/es6/#test-Map or Set: http://kangax.github.io/compat-table/es6/#test-Set http://kangax.github.io/compat-table/es6/#test-Set I will probably continue to transpile for the moment (till I can check everything). There is also polyfill.io which would only polyfill old browsers.