I really like both the e-Niro and the Kona EV for their "normal" car look and I did some hacking too. Wanted to play with the Web Bluetooth API and Svelte, so created the open source Niro Spy app (should work with your Kona too), works on iOS through BLE browser. It might be a good template for some OBD2 hacking, you can also check Open Vehicle Monitoring System repo and the evDash project.
The car is somewhat reliable on the battery side (still have SOH over 101% after 90k km / 50k miles), but the gearbox and motor bearings issue can be tricky to fix.
Also the MY2019 vehicles do lack remote climate controls and battery preconditioning (which I'm still trying to fix with the app).
