It just occurred to me how the Manage Grids window is such a good tool for many things, and one reason for this is that it's sticky ... it stays open until you close it.  It also gives me lots of room to work, as compared to a tab bar, less need to scroll to find the grid you're looking for.  I think it can be an even better tool for managing the current state of the grid workspace.  So I have a few suggestions:

 

1.  In the Name column, display the name of open grids in bold text, just as it is in these menus: View > Grids, View > Grids > Recent Grids.

2.  Enable sorting of the list to show open grids at the top.  The ability to filter to show only open grids.

3.  Perhaps have a "Last Activity" column, if that is different from the existing "Last opened" column.  (The tooltips show "last activity" in the View > Grids menus.)

4.  Have a right-click "Close Grid" option for open grids.