You can try to run the A/C unit during DCQC, but not cooling the cabin, but turn on maximal heating of the cabin.
I explain why:
Somebody wrote here, that when you turn on the A/C, outside fans will blow. That is correct, big fans will start to "cool" or "heat" the external heat exchanger of the A/C heat pump. This will blow air towards the battery.
However if you turn on A/C with cabin cooling, the heat pump will produce cold liquid on the cabin side of the heat exchanger, and hot liquid on the outside heat exchanger, and the outside fans will try to cool down the heat exchanger, so the heat pump can work with a better efficiency. But unfortunately this air is then "heated" and blown towards the battery, which will cause the battery to heat even more.
But if you turn on cabin heating with maximum capacity, the reverse would happen, the outside heat exchanger will be cold and the inside will be hot, the outside fans would try to heat (warm) up the heat exchanger, and so would blow cold air towards the battery, which might help cool the battery during QC (or at least would prevent a fast and massive heat buildup).
It's just a theory, somebody already experimented with this, but instead of heating he was trying with cooling the cabin, and he managed to raise his battery temperature. Since new Leaf has a heat pump, somebody having a new Leaf should try if it is working heating the cabin to cool the battery.
Another thing I discovered when having a closer look at the bottom covers of the vehicle was the holes on the bottom cover right before the battery. It has some holes which I think actually prevent the air flow to reach the battery, or at least a significant amount cannot reach the battery, air flow is simply lead outside under the car, making a better cooling of the battery while moving impossible. Would be interesting to cover these holes with power tape or something to see if directing more airflow towards the battery can achieve a higher cooldown of the battery while driving.