I suggest enabling Taskbar Button Grouping by app

Currently you can choose whether to preffer grouping all buttons in task bar or not grouping buttons for all applications.

I believe it will be more efficiant to select grouping or ungrouping by app for example I want to use the default state in windows - grouping all , but I want to ungroup outlook and see seperate icons for outlook mail window, outlook calander window, outlook contacts window etc.