One thing that's been in the back of my mind is Kiyoko's big fear that gets revealed to us just before the Lureling fight. In vanilla, Kiyoko's big fears are:
Wonders if she really was a good mother, and if it's fine to be out adventuring away from her children.
And
Fearful that she is too distant to Kinu, wonders if she is now obsolete after raising her.
Both are all right, and are in her character. Though we don't really see these fears manifest in the plot. I feel like they really missed the opportunity to make Kiyoko's fear being returning the the Astral Plane. It would really add some good depth, this idea that her meeting someone she's deeply in love with, having a perfect family, getting freed from her captivity, reconnecting her old best friend who just so happened to still be alive all this time; What if there's this little voice in her head telling her that this is all too perfect? This is all just a mad dream she's come up with because she's been stuck all alone for centuries? That one day she's going to wake up to find herself back in that cabin?
I present to you, in the spirit of /cocg/ my autism manifested:
Now look. I'm not saying we need to turn Kiyoko into a traumatized mess. That's Tobs level of writing. But getting locked up in a ball for hundreds of years alone has got to leave some mental scars. Her overcoming her years of isolation, maybe slipping up here and there as she forgot one random custom of Kitsune society, or Kitsune stopped doing some old custom from her days, but everyone is too polite/low status to tell her she's made a mistake until Komari or Kinu pipe up, or needing the champ to comfort her and give her cuddles and acts clingy.
We could also see this in how she handles her kits, moments where she's loving and sweet and actually showing maternal affection because they're living symbols of how she survived, reminders that she's not alone anymore. Maybe a scene where she's having that feeling of paranoia but then Kinu or one of her siblings hugs her and snaps her out of it.