Kase's actions need to start reflecting her words at some point... I mean she's already way late on that front but come on!
I did enjoy Yamada's growth and attitude throughout the chapter, the fact she still felt guilty for having those feelings shows to me how much work they both need to put into their relationship (Kase in particular). The fact that even after this chapter Kase doesn't see what she did/is doing is wrong is baffling...
I wouldn't be opposed to Kase and Yamada breaking up for a while, a scenario that can be derived from Kase losing the race, willing to stay in the dorms and Yamada just reaching her boiling point (maybe by a subsequent action by Fukami after the race is finished) and breaking up with Kase. We've seen how Kase initially reacts when she thinks Yamada has or will break up with her (she stays away until she gets enough courage to face Yamada). Have them be apart for the rest of university and reconnect afterwards in their hometown, after all there was that tidbit about Kase potentially going back after uni for work and I could see Yamada doing the same, as it's her comfort zone. Then they can have their relationship which I pray and hope that by that time Kase has matured... A LOT