One other thought if you are moving in the direction Webpack / ES6+Babel – have you considered switching the dependency management from Bower to relying more on npm? Webpack suggests preferring npm/CommonJS modules to bower modules (http://webpack.github.io/docs/usage-with-bower.html). There seems to be a decent amount of momentum in this direction. I can also envision that npm’s nested dependency management could become important to reduce ‘dependency ■■■■’ as the number of OWAs and re-usable front-end components/libraries for OpenMRS increases.