vdl-chart with multiple y-axis

Thanks @Joc O'Connor​ for pointing me in the right direction! Here's what I ended up implementing:

<script>
    function addYAxis(config, title, range, y2_series) {
        y2_series.forEach(function(series) {
            if (typeof config.data[series] != 'undefined') {
                config.data[series].yaxis = 'y2';
            }
        });
        //TODO: prevent legend overlap of yaxis2 title (https://github.com/plotly/plotly.js/issues/1594)
        config.layout.yaxis2 = {
            overlaying: 'y',
            showgrid: false,
            side: 'right',
            title: title,
            range: range
        };
        return config;
    }
</script>
 
<vdl-chart modifier="=addYAxis(config, 'Second axis title', [0, 100], [0, 2])">
  <vdl-chart-series entity="entity1"/>
  <vdl-chart-series entity="entity2"/>
  <vdl-chart-series entity="entity3"/>
</vdl-chart>

which adds a second y-axis on the right of the chart, with title "Second axis title" that ranges from 0 to 100, and moves the first and third vdl-chart-series to the second y-axis.