You compile ES6 at run-time in developer mode - ES6 compiles are cached and installing a plugin precompiles it on your machine automatically. However, if you're

You compile ES6 at run-time in developer mode - ES6 compiles are cached and installing a plugin precompiles it on your machine automatically. However, if you're developing a plugin, ES6 will be compiled on-the-fly. The summary is, It Just Works™, efficiently.