EF4 Framework has just been updated to 4.5 version - see important improvements.

We've released the new EF4 Framework 4.5 version with many new important improvements.
Modifications especially relate to optimizing the framework for web performance measure for mobile devices and dektop devices.

Since a good score of page speed is required for well optimized site we've done all that may be improved in EF4 Framework to avoid problems in analytics tools you may use. For example, demo sites didn't pass google mobile friendly test when Theme Customizer was enabled. We've excluded the tool for analyzing the site. 

As a new feature except of already available CSS and JS compressors we've also added HTML compressor to make the compressing option complex.

Web developers will be satisfied with new implemented features that come with automatic CSS files compilation.
There are also few improvements for layout builder section for responsive layouts.

Read the full changelog