Question: Is it possible to uglify all the RequireJS modules without concatenating them into a single file? (I know the other way round is possible with `optimize: "none"`).

Answer: 
I hope this is not too late to give a response. 

I was also looking for a simple, robust, flexible and highly customizable bootstrap like react grid system to use in my projects.

The best I know of is `react-pure-grid` <https://www.npmjs.com/package/react-pure-grid>

`react-pure-grid` gives you the power to customize every aspect of your grid system, while at the same time it has built in defaults which probably suits any project

**Usage**

```
npm install react-pure-grid --save

```

-

```
import {Container, Row, Col} from 'react-pure-grid';

const App = () => (
      <Container>
        <Row>
          <Col xs={6} md={4} lg={3}>Hello, world!</Col>
        </Row>
        <Row>
            <Col xsOffset={5} xs={7}>Welcome!</Col>
        </Row>
      </Container>
);

```
The way I do is go to <http://getbootstrap.com/customize/> and only check "grid system" to download. There are `bootstrap-theme.css` and `bootstrap.css` in downloaded files, and I only need the latter. 

In this way, I can use the grid system of Bootstrap, with everything else from Material UI.