Plasmoid which modifying the taskmanager to make it using the mouse wheel with the mouse pointer by scrolling up/down above the task should:
By Scrolling up
-Opens a new instance
-Restores window or group
By Scrolling down
-Minimizes window or group
-Closes window or group
And also allows hiding the titlebar for maximized windows to Save more screen space .
it needs restarting the plasma shell.