No, what I mean is...if Prussia and some other major power (historically Italy) are at war with Austria, if Prussians take one province in Bohemia, have a stronger army and have had certain events pertaining to leadership in Germany, Austrians should have an option to cave in and accept the Prussian hegemony in Germany. If Prussians decline and go on to conquer Austria proper, the Empire (provided the Compromise did not occur) should collapse, with the consequences I described earlier.
One MAJOR note, however. The armies of counter-revolution in 1848 were overwhelmingly Slavonic in composition
. The Croats should not revolt against Austrian authority - they should revolt against HUNGARIAN authority, provided that the Hungarians ousted the Habsburgs.
War exhaustion won't work - wars can go on for decades without it hitting 25%. Control of Vienna would be a de facto sign that the Empire is over - no Compromise.
Now, if the Austrians take the "easy" route and cave in early, a Compromise event should come up, with choices somewhat similar to what you described -
A - admit Hungarians as an equal state culture and change flag (somewhat ugly way of dealing with historical Compromise situation).
B - split the Empire (historical borders) with Croatia remaining a part of Austria (possible future conflict between Hungary and Austria). This should give Austria a "last chance" to unite Germany.
C- split the Empire into Archduchy of Austria/Kingdom of Bohemia and Kingdom of Hungary (satellite of Austria)/Kingdom of Croatia (satellite of Hungary in turn), resulting in some very pissed off Croats. Should give Austria the "last chance".
D- keep the Empire intact - instant and massive republican Hungarian revolt. If it controls Vienna, Austria is inherited by PRU/GER automatically.
In all cases, consciousness of Czech POPs should be raised significantly. Now if Austria does not cave in, it can either defeat the Prussians in the field while facing some major revolts in Hungary - if they beat PRU, they can still qualify for a "last chance" German unification.
If Prussians win...well, German provinces and Bohemia-Morawia gets swallowed (NO Austrian choices here. If Vienna falls, they're out). However, if Austria still holds Budapest and HUN is NOT independent as a REPUBLIC, Habsburgs can keep power in Hungary, with Croatia as a satellite. This way Austrian player gets to play on, too.