Would be nice to specify a max labelLength setting to control the label width that is used before ellipsis is shown on x-axis labels.

I see in renderUnsquish() is where you currently determine the width to set:

    // Add ellipsis if the label length is significantly longer than ideal
    if (attr.rotation) {
        css = {
            width: (labelLength > chart.chartHeight * 0.5 ? chart.chartHeight * 0.33 : chart.chartHeight) + PX,
            textOverflow: 'ellipsis'
        };
    }