"Unread" status only changed by user

"Permanently" mark tweets as unread until user marks them otherwise.
What I mean is that instead of having tweets loose their unread status when ever a column is refreshed, they will stay marked with the blue dot while new tweets are added to the column until the user marks them as old. This way it's possible to leave Hootsuite with autorefresh and still not miss new tweets when you are away from the computer.