1500 hours here, I would be very happy to see something like that in the game, I believe that was also one of the reasons behind Hordes being so OP.
Something that occurred to me when playing is that it should be possible for titles to ‘die.’ At the moment, once a Kingdom or Empire title is created, someone will have it. If the current emperor is weak and the realm breaks up, inevitably someone will seize the title from him and use the de jure claims it grants to rebuild the empire pretty quickly.
I think if a king/emperor no longer holds enough of the de jure realm (whether directly or through vassals), then upon his death that title will die with him. The title can be recreated if someone meets the requirements, but until then nobody will have it, and therefore won’t have an easy route to rebuilding the realm.
One of the problems in my opinion is that there isn't enough incentive for a kingdom to really meddle in the affairs of another kingdom I would like to see more wars to install puppet kings than wars of outright conquest if I invite a pretender from another kingdom and then press his claim for him instead of a opinion modifier I should get tangible benefits like paying tribute or an ubreakable alliance for twenty years
In my opinion, the Byzantine 'Empire' does deserve to be demoted to a 'petty empire' after at least 1204, but possibly before; so maybe that's a way to deal with it? If the Byzantine Empire becomes the Kingdom of the Straits (obviously can't have current Greece and Anatolia as they are) if it shrinks too much and the emperor dies, in practice of not in displayed name, that would be quite fitting.Wouldn't that destroy the Byzantine title in most later start dates?
3) It would be also interesting if they added for every (independent) ruler a legitimacy bar. It would function similarly as religious authority.
There could of course be titles that are excepted from the rule, kind of like how CK2 has a de jure drift exception to k_jerusalem.Wouldn't that destroy the Byzantine title in most later start dates?