haihai!
i think if we're talking sheer strength, chngbn would win. however, i believe this man is such a huge softie that he wouldn't try to Properly box against his members (exception being jisung... honk kong talker im looking at you, and well manhandling seungmin but thats not the same as boxing) and would be too afraid to hurt them? but also i feel like minho has trained boxing more so he would have the advantage with technique and he seems to be a really good boxer so overall i'd say minho. i also think changbin would lowkey be scared of minho when it comes to boxing for some reason lmao

as for that last part. seungmin definitely would be there drooling. and now im having thoughts of underground boxers fighting for seungmin or something.... hmmm. much to think about