Hello restoreoregon,
This is easier than you might think (only 3 line from what I can tell), and it is more php than javascript!
You just need to get the organizer name of the event, set it in an array, pass the array in as additional data to be converted to json and then call that new object in the tooltip template.
You’ll have to style it how you want, but this shows how to get the organizer name in the tooltip. Lines 188 and 192 on single-event.php along with line 20 of tooltip.php are the only changes from the base template.
https://gist.github.com/caseypatrickdriscoll/97bae844173aad2fe65e
Does this make sense? Let me know if this doesn’t work for you.
Cheers!
– Casey Driscoll