A look at that V/A module says that there is nothing on that board to prevent a religious experience crossing it and going up to whatever you have plugged in. Possibly making the whole thing live and … exciting.
Does it tell you your power factor?
If they were clip-on transformers, I might consider one. But we have 2 phases and the breaker box has bus bars ^^;
A typical Japanese home will have 2 phases and a total of 6kW. The 60A breaker is not per phase
Those two devices are PZEM-004T. See this previous post http://domoticsduino.blogspot.com/2018/10/home-automation-system-two-pzem-004t.html