this is a great example. remember the word "custom" in the example can be what ever you want (elephants, apples, ), so you can explicitly tag loads of information here. the hit is object size. THANKS!!!!

Not really, anything needs to be processed... What you are referring to is perhaps the turboThreshold in Highstock, where we only accept arrays. That relates to my second example above.

Yes, but if I understand documentation correctly, currently using objects for data points adds significant performance penalty because object is interpreted as options for each point. Allowing just inactive objects instead, which would not be processed in any special way, but would just allow additional data to tooltips, would improve this, no?

Please implement this. Was is currently available is not enough. Currently you can or use slow objects (which are specially processed and keys influence points) or just numbers. Can we please get something in between, for example, an array with: [x, y, data], where data can be arbitrary object which is passed as it is without any processing to formatter for each point. This would mean that points can still be drawn fast, but there is additional data available when displaying tooltip.

This can help implement such interactions like brushing and linking. Or displaying additional metadata for each point.

You have full control over each point's tooltip text using the tooltip.formatter. Custom options for each point can be passed, and the formatter can reflect this.