Highcharts treemap slow rendering upon drilldown

问题:

I have built a Highcharts treemap with quite a large data set. There are two levels in the hierarchy, with about 300 nodes at the top level and as many as 83 children of one of the top-level nodes. When I click on one of the top-level nodes, the treemap of the children nodes is very slow to render (~8 s). I am using Chrome, and I recorded this click function in the Timeline feature of Chrome Developer Tools. It turns out that the vast majority of the time spent rendering this image occurs in functions that Chrome labels "Recalculate Style" and "Layout". In each of the Layout functions, there is a warning "Forced synchronous layout is a possible performance bottleneck." Is there an easy way to batch these operations or otherwise reduce the number of calls of this type? I am finding that the resulting delay is making the chart prohibitively slow. Thanks for any assistance!