IMO, what Genesis told you was nonsense, hope this was just an employee handing out misinformation and not the corporate position.
- If perchance there was failure while charging with a 3rd party adaptor of either the vehicle or the charger, they would need to prove that the root cause of the damage was the 3rd party adaptor in order to deny warranty claims. While it's possible that a cheaply made adaptor could cause damage, adaptors from the likes of A2Z or Lectron should not cause any issues.
- To say that the Hyundai adaptor is not compatible with the Genesis vehicles is B/S. While it's possible that the Hyundai adaptor will have a different p/n than the Genesis adaptor (have no idea why they would do that unless they want to make the Genesis adaptor appear to be "premium" for a "premium" vehicle), the Hyundai/Kia/Genesis adaptors will all be interchangeable with each other.
- All the adaptors are doing is connecting one well defined controlled interface (CCS) to another well defined controlled interface (NACS). There is no magic here, no software, no firmware, just wiring, thermal sensors. Adaptors need to be designed to handle the current and heat dissipation, not much else there.
For the record, I have an A2Z Typhoon adaptor, use it to charge my Polestar PS2 and my Genesis GV70, no issues at all.
In hindsight, might have been better if all adaptors just came from Tesla (or some other single source) instead of having each EV manufacturer designing their own adaptors and stating that it can only be used on their particular EV model, else you void warranty.