So, I finally did it. I bought that little flat battery expansion plug for my Mavic2 Zoom. It's made by StartRC, I think. I used a lighter weight 4200mah LiHV graphene battery and connected to the drone after starting the drone up with it's own battery. I flew a route which I know only gives me like 5% battery to land when returning to my home point. But with this battery mod, I had 55% battery left!. I was amazed.