My final implementation that works, looks something like this:

    CGFloat zoomScale = fmaxf(0, self.chartView.zoomScale);

    CGFloat interval = fmaxf(1, (count / numberOfLabels) / zoomScale);

We are still fighting this issue. Was there a new build we should be using for the fixes you mentioned?

I can try turning off the smart axis panel, but a similar issue happens when the chart fills up with points. Except, I see the "..." - even when zoomed in.

http://bit.ly/25f5GqF

Gif: http://giphy.com/gifs/l3E6DWKGxooe9vfRm

Classes involved, 

IGChartView

IGLineSeries

IGCategoryXAxis

IGNumericYAxis

IGCategoryDatePoint, we use these to preserve the NSDate, which is used later for CSV output. We set the label property via NSDateFormatter.

xAxis looks like...

        self.xAxis.useSmartAxisPanel = YES;

        self.xAxis.smartAxisAngle = 45;

        self.xAxis.smartAxisFontSize = 12;

Do you have a build I can test with?