I'm still pretty new to the IEM scene, would you happen to know where I could find an aftermarket cable for these? I haven't exactly been able to figure it out.
So what you would be looking for is a custom 0.78mm 2-pin cable. There are many websites that offer custom cables that are hand-made such as Null Audio. If you are looking for more reasonable prices (and quite literally identical performance) you can always shop on Penon Audio. But don't let the snake-oil salesmen get to you, an aftermarket cable makes no audible difference. Anyone who claims otherwise is either trying to take your money or is succumbing to confirmation and expectation bias.
https://medium.com/resonance-reviews/kinera-h3-review-a-triple-threat-underdog-16b2043ba009