Nope, you would have to play non-ironman then save and reload as them. Jerusalem also has its own set of ideas, but ONLY if you use the save converter for ck2. Otherwise, they get generic. It's silly.
Dang it. It would be nice if they added a little decision for cyprus so they can form jerusalem, and either get the converted jerusalem ideas or keep the cyprus ones (i don't know what ideas converted jerusalem get, but usually converted ideas are kinda silly like the colonists for israel).