Stacking connectors on the battery will lead to bad contact problems. I got me a marine grade busbar, and fed one battery connection to it, and connected my devices to the busbar. Of course each device must have an individual fuse of its own, but you already do that I am sure. You can place the busbar where convenient, but make sure you put the little cover on that should come with it, so it doesn't short on anything. No bad contact! Everything works!