Tooltips are very usefull but they just disappear too quickly. It would be nice if we could adjust the display duration of a tooltip from within the property panel. Indeed the default setting might be ok when using basic tooltips but when choosing to display a chart inside a tooltip, you might need a bit more time to understand the chart and read the data.
Tooltip display duration setting should offer a duration input in seconds or milliseconds as well as the option to choose 'continuous display' so that the tooltip is displayed as long as the mouse remains on the item.