I have been trying to set custom tooltips for custom task pane buttons, that is, close button and down-arrow button. I have seen they already have a tooltip set by default but I would like to change it to show a custom text. Is that possible? or even is it also possible to change the tooltip style?
The Office/Outlook extensibility model doesn't provide anything for that. There is no trivial way to specify a tooltip for these controls. The CustomTaskPane interface doesn't provide any property or method for that.