I don't own a Niro (yet?) but I road tested one recently.
In my opinion, the surge described is typical of the dual clutch transmission.
I have the same type of transmission in my current car (VW).
If you are used to conventional transmissions (I.E. with a torque converter) or a CVT, a dual clutch will never be as smooth and seamless, especially at low speeds.
It's just the nature of the beast.
Keep in mind that by design, it's a manual transmission. So like a manual (even with a good driver), it can be jerky.