Rejected. Frequently rejected, in fact.
As Vita says, this feature would be vastly too likely to increase concentration of power.
I did not see this anywhere on the FR list?
Additionally, despite your explanation, i still don't see how diversifying the responsibility actually concentrates power. Could it be that I am reading it wrong? Because in my mind, A duke would only to be able to choose an heir that was beneath him in the hierarchy, for example, as opposed to a King or another duke. A margrave could only appoint a knight of his region, etc. no rotating titles that way.
