Please make succession crisis in Hungary a 10 year disaster if player chooses to elect János as regent.
Going with the Hunyadis' modifiers (Habsburgs spurred and remove historical friend) doesn't resemble the situation well, the player can easily remain Austria's ally. So IMO these events could ruin Hungary-Austria relation before they are spurred and removed.
Also there is a lot of good event material happening in Hunyadi János' regency.
F.E.:
1445 Wallachia captures János, only a threaten war from the february diet can save him from being sold to Ottomans.
The May diet elects János as one of the seven captains of the kingdoms regency council.
1446 june In the absent of Ullrich of Celje (leader of the Habsburgist faction) the diet elects János as regent
1444-1456 Jan Jiskra occupies Slovakia region continously after that he joins Mátyás and he will be a great general of the Black Army
1445 János punishes Wallachia
1446 János punishes Ullrich who flees to his Styrian lands, János follows but Austria denies military access János raids the duke's lands too for that.
1448 János leads an army to help Albania, Serbia captures him on the way back releasing him only for a juicy ransom
1450 János acknowledges P. László's claim on the throne
1453 János abdicates in favor of Postumus László
1456 László dies triggering Mátyás' coronation
In 1440 Habsburg Albert's wife stole the crown so Wladyslaw of Jagiellon was never crowned properly, Postumus had it but he died abroad, only decades later, Mátyás could buy it back for an enormous price.
If Hunyadi János dies in battle or siege, the sick little Habsburg (1-2-1 Postumus) (who is not Ladislaus, but László in Hungarian) gets the throne for free.
Most times also gets the throne as a 3-3-2 in Austria.
So the player doesn't get to choose between secondary member of PU and Mátyás, instead comes our double agent 3-3-2 / 1-2-1 twin Postumus.
This thing (and restarting to play this part again and again) is really making me mad.