Display current window title as taskbar button label instead of app name for grouped tasks

Is there any way to do so?

Also, it would be better to set the delay for displaying the thumbnails of the grouped windows in the taskbar to 200ms by default with a timer on its own, as changing the current timer with

kwriteconfig5 --file ~/.config/plasmarc --group PlasmaToolTips --key Delay 200

is affecting the delay of the tooltips everywhere, and the result is not so good.