I think the Karen/Zee dynamic is worth exploring more, their friendship is one of the most interesting things in the show.
Obviously right now Zee is the dominant member of the friendship. It would be interesting to see Karen slowly grow to be more assertive, and Zee slowly grow to listen to her and take her direction. Faust could do in this show what she was unable to do in the Horse Show, and actually allow the shy yellow one to permanently grow out of her shyness and find her voice, with the encouragement of her prissy friend with the purple hair. Basically let Karen take the lead in their friendship from time to time, and let Zee learn how to listen.