CSS minification - no longer part of css-loader - should we add cssnano to nwb's default postcss-loader config?

[insin]

css-loader@1.0.0 no longer uses cssnano to minify CSS in production builds, do we want to add it back by adding cssnano to nwb's default PostCSS plugins?

Are there any potential issues with minifying CSS before it reaches css-loader?

Here's a small Bootstrap 3-using app with css-loader@1.0.0:

File sizes after gzip:

  dist\vendor.719d8810.js   47.65 KB
  dist\vendor.c100adf1.css  20.55 KB
  dist\app.222440ae.js      1001 B
  dist\Child2.b09783a1.js   632 B
  dist\Child3.3b34553d.js   570 B
  dist\Child1.3e7352a2.js   529 B
  dist\Child3.f672301d.css  109 B
  dist\Child2.1b04ae73.css  108 B
  dist\app.dd18676c.css     89 B

Here it is with cssnano({preset: 'default'}) as part of postcss-loader:

File sizes after gzip:

  dist\vendor.e8457d03.js   46.93 KB
  dist\vendor.c01d6bfd.css  19.08 KB
  dist\app.0c3ec42a.js      997 B
  dist\Child2.6c0a0ede.js   631 B
  dist\Child3.ba15e3f9.js   570 B
  dist\Child1.4104e1cd.js   528 B
  dist\Child3.41174980.css  98 B
  dist\Child2.da694fa7.css  97 B
  dist\app.66900423.css     81 B

[insin]

The mini-css-extract-plugin docs have some guidance on this:

https://github.com/webpack-contrib/mini-css-extract-plugin#minimizing-for-production