it's an enderchest, so to access that chest, you just need to access any other enderchest of the same colour combination
I agree, which is why I said 6 enderchests + 6 sorting machines.
Right, only reason to access it is if you want to change the color, no argument there.
You would have him build 5 extra ender chests instead of 1 router and 1 relay? Even then, removing unsorted items becomes either a manual chore or some tedious workaround involving a delayed filter/sorting machine.
Can you explain why you're opposed to the router idea?