I use the tooltip feature right now and a hotkey "numpad 0" to get the folder sizes. This works fine, it would be useful to just hover with the mouse over folders too. And maybe a good idea to implement a new "hover & pause" event!? Maybe it could be used for some other tasks as well.
Yes, I already did that, thank you! But I would like no tooltip at all, because it's not needed at all. The folder size is displayed already just an inch next to the tooltip: snapshot
But a simple "Calculate folder size on mouse hover & pause" option in Preferences would be perfect for me.