Multiple roles for same actor with an Attribute for each role

Sometimes, when you have a single actor playing multiple roles, you want to give a different Attribute to each role.

For instance one actor playing Tom, Dick & Harry where Tom is credited but Dick is (uncredited) and Harry is a (credit only) performance because the role was cut but is still listed on the cast roll

Currently I can add all of the Attributes but you can't tell which attribute applies to which role

Or, a more specific example, in The Life and Death of Colonel Blimp (1943) Deborah Kerr plays 3 roles. She plays Edith Hunter in a 1902 sequence, then she plays Barbara Wynn in a 1918 sequence, then finally she plays Angela "Johnny" Cannon in a 1940s sequence.

I would really like to add the dates for each character as an attribute to each role, but I can't separate them out

I'm sure that there are many other examples. See GetSatisfaction article
How to credit an actor that needs an as attribute for one credit but not for others for some more examples

Thanks

    Steve