Redundancy and flexibility.. add a second panel that is independent but have the wiring/switching flexibility to have one integrated unit. I have double Anderson plugs in the 'trol and will do so in the CT, one for single system, the other to crossover and make the banks combined. I'd like to just have an old 3-way switch (marine) but thought it would look odd. I might mount one in the CT, have one in the CSU which I will move to the CT.