The beananimal overflow is never a bad idea no matter the tank size. I question the use of what looks like check valves on the returns as they use a metal spring to push against the back flow of the water. Those springs tend to rust after a year or so. And those did not look easily removed in the small space of the overflow.
Also with dual returns in my experience being fed by a single pump even if split evenly tends to favor 1 side or the other. In any system I have designed I eventually remove 1. Putting in a ball valve on the dominate side will help to regulate it if you are planning on using it for primary water movement.
Also with dual returns in my experience being fed by a single pump even if split evenly tends to favor 1 side or the other. In any system I have designed I eventually remove 1. Putting in a ball valve on the dominate side will help to regulate it if you are planning on using it for primary water movement.