Mission impossible? In my campaign, it's yes and no.
But, first of all, allow me to say that this is a great mod, with potential to be... well, greater.
I've started (but not finished) some Late and High Era campaigns and I'm still working my way around the very interesting new feudal system with all the other benefits and changes. It reminds me a lot of Europa Barbarorum, which is great.
While the Kingdom of Jerusalem campaign was pretty straightforward, building a Templar/Crusader army and showing Saladdin who's boss, the High Era Cyprus campaign was... different.
With two crusades called by the Pope on my request (I basically have Clement on medieval speed-dial), the Holy Land was retaken, the kingdom of Jerusalem rebuilt... and the only city where I can recruit any decent units is Cyprus. So far, it's working but I only have so many fleets and so many recruitment slots. Armies are shipping out and in for re-training every turn, as I'm battling the Egyptians and the Khwarezmians on several fronts, with the Turks encroaching on Armenian territory to the North.
Is there any reason why Cyprus can't proclaim Crusader State on any other region except Cyprus?
And wouldn't it be great if conquering Jerusalem and setting the capital there could change the faction (back) to Regnum Hierosolymitanum?