I have built this contraption to capture and cool production of my gold volcano. It fortunately works well, but I have noticed the weight plate is only registering about 30 kg (may differ between eruptions) while there is about 470 kg of gold sitting on it by the end of eruption. The gold was deposited gradually as the molten gold from the volcano was falling into the pool. Save/load fixes it.
Have a volcano product fall into a pool of water onto a weight plate. Check the weight registered by the plate.