The additional power connection will not help much. The Pascal chip achieved "only" 2.2GHZ in tests. Regardless of whether the card had an 8-pin or 8+6-pin.
I simply claim that the 6pin connector is needed for the LEDs and the additional fans. *laughs
You will not need more than 8 pins. The Pascal architecture is extremely economical and can reach 2.1ghz with the 8 pins without problems. Probably even higher. Well at some point it doesn't make sense to go higher either