Echo JS 0.11.0

This *could* be useful if you're creating a leaner application where responsiveness on mobile or otherwise very limited devices as a priority.

Outside of the above context, I'm not sure it offers that much above current bundlers, especially if you are limiting support to modern (self-updating) browsers.

Thank you for your feedback.

The advantages are: 
- no tooling is required
- there is no configuration effort 
- and the initial loading time is short.

Disadvantage: 
- it uses blocking requests.

I'm planning a "diagnose-script" which produces a console output that lists the required polyfills. Grouped by "initial" and "delayed", so that you can preload them.

Yeah, diagnostics would be really beneficial... possibly something that can generate a bundle from the polyfills that get added.  Of course, would need to run across several browsers and aggregate the results.

Only including what you actually need, vs say the babel-env fills, that include everything missing for your target, even if you aren't using it.

Blocking requests can be seriously nasty in practice though... I had to use them for SCORM implementations at one point.  And if you have a spotty connection as a user (think mobile) it can/will get particularly bad.