I have the 3.25 gallon Berkey. I don't fill to capacity.
I adjust how much water to pour in the upper chamber by how much water I consume between cycles. Minimizing the amount of water that I have to dump from the lower chamber into the gray waste tank each cycle. I dump the upper chamber only when there is visible particulate matter. I inspect with a bright flashlight.
Tilting the Berkey allows more water to discharge from the spigot, otherwise that is around 1/2 gallon of water wasted along with adding unnecessarily to the gray tank.
I recharge at night, and I only move during the day, when the upper chamber will have the least amount of water, which is about 1/2 gallon below the filters.
For movement, I place the Berkey into a crate on the floor, and stuff padding in the corner to protect the spigot. The crate is secured by cords.