Hi,
From your source code the tooltip will fire a refresh event every time it refresh its content and position. However from my test, looks like it is not fired. Is there any thing wrong with my code?
http://jsfiddle.net/6jyL3rxh/
Inside tooltip object, you can set options which should be triggered from the core. Notice that tooltip.events it's not defined in the core. I showed you a way how to 'get inside' the core to do some changes.In docs, there is no something like tooltip.events.refresh.