I increased my country by 50% in 8 years, so it was time to recover.
I allied Hesse who I want to be the next emperor. Unfortunately that failed and Austria got reelected.
I finished my mission to convert main Bohemia and get 100% religious unity (through stacking tolerance for heretics mostly), and got Hussite Center of Reformation as a reward. Unfortunately it's the only one that can spawn.
I still had some time, so I went to a small war to convert a few HRE minors to the true faith.
And then it was time for the big event. Restoration of Union CB on Hungary! Austria was still allied to them, and England declared itself Defender of Catholic Faith, so I had to distract both (on opposite sides) with a small war against Venice.
Venice was also conveniently fighting Ottomans, as they guaranteed Orthodox Albania. I don't really care about their war, as long as they don't interfere with my legitimate claims to Hungarian throne.
I got PU over Hungary and Croatia without too much trouble - and then by event Hungary inherited Croatia so I only had that one.
Unfortunately Venice war was going tragically poorly. Venice had 10 war exhaustion and Ottomans sieging them down, so I thought I could just wait them out a bit. Then Ottomans peaced them out, took just a few provinces, and as Venice was non-cobeligerent, that was enough to completely wipe out their war exhaustion to 0. I hate this mechanic. Even worse, Venetian ally Savoy inherited Burgundy and all their vassals mid-war.
They started having completely ridiculous demands, so I had to spend crazy amount of money on mercenaries. First I managed to get Savoy and their far too numerous subjects out of the war. Then France attacked England, drastically reducing English interest in defending Venice. A bit of fighting later Lucca also white peaced. Eventually Venice, supported by just Naples, agreed to a white peace.
The war left me with 500 debt, which isn't really even such a big deal.
Imperial Diet demanded that Savoy release Burgundian lowlands, and they complied.
I was briefly a Great Power, but that only lasted a year. By my favourite metric of income, I'm actually 4th in known parts of the world after Ottomans, Mamluks, and England - but that's just my two gold mines, both developed to 10dev.
All that finally unlocked a non-HRE expansion route for me. I can fight Balkan minors, and then maybe deal with Ottomans - not by myself, but maybe if I could get Poland or Austria to join me. There's still even leftovers of Byzantium in Morea, they would make a nice vassal in longer perspective.
If I had any mana, and so far that's not going too great, I'd love to invest in diplomatic ideas. Renaissance will be in Praha in 1471, and I'll just pay the full price for it right away.
There's no hope for any early Hussite League, I can barely fight Venice to a draw with Austrian help, fighting the whole Catholic HRE would be crazy. Hopefully I'll make it before Protestantism appears and they setup theirs.