"Add" mode for feathering many objects.

Also another feature to aid the user when applying feather to a group of objects would be an "add" function for feathering...

This would mean that you could add or subtract an amount of feather to a group of objects regardless of what the feather amount was for each individual object.

You could select 10 objects of different amounts of feather and hit the add button then you could move the slider to add or subtract say 5 pixels of feather to the whole group ETC...