See it's the fact that Jax and Zooble's relationship is so interesting to me. I think it was pretty much immediate animosity on both sides; Zooble joined after Gangle, and Jax at that point was already hostile.
See, Zooble has always been self-assured in every part of themselves /except/ their body, and by extension probably their identity, since the two could definitely be linked. And I think that drives Jax insane. A confident non-binary person? Someone who goes against all the norms? It's no wonder Jax consistently picks on them.
See, Zooble recognizes parts of themself in Jax. See, Zooble knows Jax is only mean due to insecurities and inner troubles. I remember after episode 6 aired, people called Pomni emotionally intelligent because she recognized that Jax pushing her away was bullshit, and that they /DID/ form a connection, and Jax was being an asshole. And they're right! Pomni is emotionally intelligent! But so is Zooble, maybe even more-so. The difference between Pomni and Zooble is exposure to Jax (Zooble's been around longer) and willingness to put up with his shit to reach inside and see who Jax really is (Zooble is not, and no one should expect them to. Not wanting to bond with someone who is cruel to you and others is perfectly valid).
It's the maid dress confirming to Zooble that yeah, this is an egg for sure. It's the beginning of episode 7, when Zooble very openly admits that maybe being able to choose their own body isn't such a con, and that if they still have issues, they /talk to those they trust/, very clearly telling Jax to do the same, less clearly saying that they understand how it feels to be in a body you don't like. It's Zooble telling Jax to sit back down, don't wander off and just kill yourself abstract, you're a part of the team. I don't like you, but I care for you, and I want you to be well.
See, Zooble doesn't sacrifice their personality and feelings to get away from Jax, they double down on their authenticity, and I think it scares Jax. Immovable object meets unstoppable force, real authenticity meets hallowed out shell. Zooble is a constant work in progress, and accepts that they're a work in progress, may always be a work in progress, and Jax can't stand the thought of change, of being anything else. There can't be an in-between moment, it has to be either hard right or hard left, and staying right where he is is easiest, so Jax stays.
Zooble is complicatedly grief-stricken when Jax abstracts. "Of course he'd wait until we couldn't do something," they say. It's sarcastic and accusatory and said in a very defeated voice. Obviously Zooble doesn't believe Jax abstracted to get back at anyone, but Jax was a jerkwad, a tormenter, and someone Zooble saw was very deeply hurt in ways that resonated deep within themself. They're feeling as many complex emotions as Gangle. It's hard to be sad for someone you hated, who hated you, not just "hard" as in "I can't get myself to be sad" but also "hard" as in "I'm sad and it's causing me distress since this person was so awful to me."
Zooble never reached out, and that's okay, it's not their duty to do that, they didn't have to, but I think it eats away at their psyche. "If I had just given him a chance, if I had just pushed a little harder," etc etc, even though nothing would've changed and it all would've ended the same. "At least I can say I tried." But Zooble /did/ try, many times, it just "wasn't enough" because they weren't coming from the same angle as Pomni. Never mind that nothing would've ever been "enough" since Jax had dug his grave and died in it, long before Zooble or Pomni joined the circus. It's the tragedy of Jax; nothing done by anyone else could've prevented what happened, only Jax could have, and Jax didn't, and now he and she is dead.
I just want to mention that Zooble was the one leading abstracted Jax into the pillow fort at the end, sacrificing their own body parts in hopes they could help Jax, even just a little. The body parts that Zooble has become more and more comfortable with experimenting with and changing and mixing and matching, all to play a part in rehabilitating someone whose mind might be long-gone for all they know, but deserves kindness all the same. Because that's who Zooble is, a team player and kind person who knows what they're worth and knows what others are worth, too.
Zooble may never be close with Jax, and that's okay. I don't think they'd ever get along in any universe, and that's okay. They have different interests and hobbies and all-together, may never do more than simply cross paths. But I think Zooble can care at a distance, /does/ care at a distance, and that's okay. I think that perfectly suits them and her.