Since Medieval 2 doesn't let you just select an heir like in Rome 1, I find EB2s work-around to be pretty smart. I understand the hard-coded limits, so being able to just give influence to whatever general I want, at whenever time I want, in order to pick the next heir to be pretty useful.
Great job EB2 team.
-edit-Oh, I forgot to say, how do you personally use this feature when role-playing? As the Romans I don't use it.