And no historical examples of religious splits, once entrenched, of being restored outside of near complete destruction like what happened with the Cathars. Which is why Christianity in Europe f.ex. has mostly turned into a national matter.
The "keep the Pontifficate" agenda was completely impossible and what's worse, it didn't even fit within the scope of the game. No wonder Kasper went crazy and gave up along the way... I spoke to him a lot, trying to help and I can say that the pressure definitely got to him. He basically had the agenda "make every temple domain player do as you say", so it spread beyond holdings, RP and GB's and became a uniquely diplomatic agenda - one where he had to beat or convince all of you OoC as well as IC.
Compare the PeTG agenda, or any of the landed agendas. A lot of them had clearly defined (draconian) goals.
He should just have done the same as me, ignore the (much easier OIT RoE 1) agenda and approach it sideways, hoping to catch Bjørn off guard with some crazy idea like I did with the CoT.
Religious splits being restored would be akin to the Haelynite temples uniting under one temple again. That's a religious splitting. And I agree that that happening would be next to impossible. But it's not at all the same as retaining the "papacy" indefinitely. And there are several examples of popes being deposed, exiled, killed, as well as other popes being elected, supported or even installed by secular powers. He also had quite a few things going for him - being the only one (so far and as known to the public) able to detect dopplegangers, owning huge parts of Ilien following the war and having quite a large chunk of the CoT warchest safely stored away for personal use.
The agenda was not impossible. No more than the Avenese agenda to regain three out of five lost vassals was. In fact I would probably have enjoyed aiming for the CoT agenda more than the Avanese version as it revolved a lot around political maneuvering and my own had me facing five realms terrified that I should try to do, what my agenda wanted me to do, which meant I would likely have to use force in one form or another to make it happen. Heck I was working towards the throne (very very slowly) and I thought that an easier goal than my agenda. If one of Aubrae's sons became Emperor, at least I'd accomplish my agenda by proxy.
That Wallac managed to alienate most people by ordering where he should have been asking and frothing at the mouth when confronted by his borderline tyranny made the agenda harder. But even that didn't make the agenda impossible. Convincing us OOC should not matter at all. It's all about the IC. And IC he did not put forth very convincing arguments.
It's a shame that the agenda got to Kasper. I think, and I have many a time, that Kasper would have been a lot happier in a landed realm where his playing style would fit better in, and diplomacy wasn't alpha and omega but just one of many available tools. But things went as things went and the outcome can't be changed.
And with regards to pontificate, let me have a crack at it next time, and we'll see what I can get away with