I agree but I also think that if she composed herself it's because a lot of people were watching and Minsoo had already been humiliated. She just tried to be mature I guess to end it quickly. Minsoo isn't really crazy but more delusionnal and even though Seol clearly has changed through the chapters she isn't aggressive (usually) nor mean.
I get what you're saying but i felt like Seol was also humiliated, like to have someone attack her like that in front of a crowd is mortifying. so while i think she did the right thing by stopping with the barbarous physical fight, she should have followed it up by using her words to tear Minsoo down even more in front of everyone so that everyone knows what she has done. that would have been more satisfying imo
i wanted Seol to rip her to shreds with words and just completely mortify and disgrace Minsoo by exposing the truth of everything she has done. the only good line Seol had was at the end after everyone had left. the fact that Seol composed herself after being attacked by Minsoo was unrealistic, no one is gonna try to be rational with some crazy person that just attacked them. Seol's emotions felt a little fake towards the end idk ¯_(ツ)_/¯