If you use "proper" parts ;), Gorilla glue becomes optional.
My Big Baby breakers box has bosses on the bottom to attach it to the wall. Insulated mini-buses are screwed to the box from inside, and because of those "bosses" the screws on the buses don't protrude through the box too far. I still put Crazy Glue under the buses, but it would hold without the glue as well.
Big Baby Box - note the bosses with mounting holes. Holds 2 buses and 4 breakers. It's smaller than it looks, 8x5x3 inches.
Insulated mini-bus, red Pos and black Neg. With buses raised on the insulators, it is also easier to access them than if they were flat on the bottom.
With 2*250W panels I didn't need this box for solar cable, obviously. You don't need a J-box for 2 panels in series. The box is for wiring battery, loads and controller.
