Synchronized tooltips and cursors

[life-of-e]

I want to create multiple charts on a page that all have the same X axis but different Y axes and then, when I hover over one of the charts to bring up tooltips (and their related cursors), the other charts will have their tooltips/cursors appear as well.

I currently use external tooltips and callbacks to get the style I want so I want to be able to keep that. At the moment it seems that the two charts are treated independently so I get tooltips on one but not the other.

Note this is still on version 3.