yes, seller sent me the wrong drivers. I got a full refund. Problem was solved quickly and nicely so I can recommend the seller. Its all good! :)
2 cells combined with a buck driver is not enough to drive an MT-G2 properly regulated at high amps.
I would go with 3 cells and resistor mod if you want higher than the 6,9A you measured.
Im not sure if the driver will handle/survice to be used with 4 cells.. And if it is, I im not so sure that will increase the amps. Feel free to try it an report back in this thread.