Support kde plasma activity window filtering

Hi,

I am testing using plank with kde plasma activities. I have manage to have for example two activities: office and system.

I can make the office plank ( launchers: mail, irc, g+, notes, gmail, hangouts ) only show in the office activity, as well as system plank (files, terminal, settings) only show in the system activity.

All works well except that plank shows all the windows of all activities. ( so if mail window is running on the office activity, its running launcher also shows up in the system activity ).

Example of problem in the screenshots. In the system activity, it should not show the irc and gmail window.

Having this filter by activity would be awesome !!!! Since plank uses little memory, i wouldnt mind having a specific plank for each activity. ( especially the most used ones )

Thanks !