Went phenomenally well for me! They were apologetic, changed everything they got wrong and added some forms they missed and filed and I felt simultaneously way more assured about the process and also way more concerned about the glaring errors they missed and probably did also in the past that I just didn't notice lol (they even spelled my name wrong lmao, used my short nickname and missed my middle initial vs my full name despite having filed my taxes correctly last year with my full proper name)

OTOH I have another friend who sent so many corrections to his CPA his CPA sent him a pissed off reply telling him basically never to do that again so ymmv lmao