Yeah, that sounds like it could have been the problem. If the data range on the axis is much larger than the tick frequency being set, the chart will be rendering a very large amount of tick marks and grid lines. I found earlier that I could make a chart hang by setting a large data range and then setting a very small tick frequency relative to that range.
I'll raise an issue in our backlog to investigate the point at which this becomes a performance issue, and whether there are things we can do in the chart to mitigate this.
Anyway, I'm glad that you've gotten your chart working as you'd like. Good luck with your app development!