Is that toy UL listed? There is no way I would even consider using a device like that.

First off, the size of the enclosure does not conform to current NEMA standards regarding free space in the enclosure for wire radius limitations, the meters look like something from Radio Shack, and you cannot have live terminal components in the wire chase. That's just what I see on the outside.

I design my own for use in bus conversions and my own home. Mine are automatic and are mechanically and electrically interlocked between the grid, (shore power) the genset and the inverter. They also automatically ground faults
and will not connect to shore power if there is no ground.