As someone who liked Kota but did not call him one of my favorite characters, I have to say this build to explore his sidequest was very well done and definitely makes me like and respect his character more. While it was never very subtle why he 'meddles' with you and Asterion's burgeoning feelings for each other, doing his route very much fleshes out the experience you get when chatting soulmates with him during the main story when he's drunk, and it works very well. All of the peeling back of Kota's layers and guard really does pay off with the extra scene at the end of chapter 17, and you really feel the character growth from him and feel great with how you and the rest of the staff come together for him once he's ready to open up and accept help.
I've only done one playthrough of it so far, but I'm definitely interested in changing up the other guests and pressing Kota for his take to see what he has to say. I'm too nice to push boundaries even though the MC can tell Kota's already caught on and flipped the script on us before we even began, so I can't wait to see more of his unimpressed face as we push our luck too far.
I really appreciate the effort you all put in to make the 'hangout routes' feel like full main story content this way, as opposed to the much more static current hangout with Luke. I especially love the execution of the chapter 17 scene between the panning between Kota and the rest of the staff - certainly the only way to really have all of the characters be on screen and have it not feel too busy, and then Luke breaking Kota's melancholic thoughts and dimmed background by actually moving up to him was a great touch. Likewise with the playing of Kota's theme(s) at proper times and whatnot.
Also, the Hinterlands 'shortcut' is extremely well executed! Not just the fact that it's there, but the framing device as a conversation with P and the MC is top notch. I feel like all I do is fawn over y'all in these posts, but again I'll say it, the way you play with the medium and keep things more in character with how you handle the player is just such a wonderful experience that blows everything else out of the water. Kudos again.