@votemike,
Exporting chart with toolTip is not possible as of now. However, indexLabel can be used to show extra information over the dataPoint, which can be exported using the exportChart method. Please take a look at this JSFiddle for the same. If this doesn’t help kindly brief us further about your requirement so that we can understand it better and help you out.
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Indranil Deo
Team CanvasJS