I propose making Hussite wars more "flexible". Let the countries, which organize the crusade, be able to resign or join the Hussites. Then they could have three options:
A. Defeat this heresy!
As in the original "Aberration" + relations with Bohemia -150 (-100?)
B. Let's interest in our internal problems instead.
Stability +1
Relations with Bohemia +25 (+50? Another value?)
Maybe something more?
C. Fight for the Hussite faith
Alliance with Bohemia, relations +150
Aristocracy -2, serfdom -2, innovativeness +2
Relations with Papal States -100
I think we can add something here...
However, in my opinion, this event could not match Bavaria and Hungary, the main organisators of the crusade.
Otherwise, I have an idea about totally new order in Central Europe, but I think it's a topic for another thread.