Honestly I feel like it’s more in character than him saying I love you, he’s always been one to put others before himself, whether that was his grandma or Jaekyung, he’s never once thought about his own condition or happiness first. He knows that this is going to affect Jaekyung’s abilities in the match, whether he knows it’s because Jaekyung loves him or, as he thinks, because of the jinx, and he doesn’t want to end up harming or becoming a burden to him. It makes sense that his thoughts are more akin to his harm being a problem for others more than for himself imo
Yes it’s totally in line with his character so I’m not even gonna complain but I find it funny because realistically anyone dying should generally feel sooo scared like “I don’t wanna die” or at worst think about the people that really matters like “take care of my grandma” but No. It makes sense tho this is just a BL not reality and I like the eccentricity.
I re read the chapter, and I think I kinda agree. Its still cheesy but it also shows that Kim Dan always puts others above himself to the point he can be dying and it's almost like his biggest concern is how his death/injury could inconvenience others. Which is sad, and also line with his character, with low moods/self sacrificing etc.

How can Kim dan who has just been STABBED and who thinks he might die choose his last words to be 'sorry I can't help you with your jinx' and 'win the match' like???? It feels so off character and sillyyyy and cheeesyyy. I would've thought it would be 'look after my grandma' or 'I love you' or even 'I'm sorry' but instead it's about the match??? How is the match on your mind after being stabbed? What on earth