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?
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.