Honestly i dont get people saying talking about the plausability of descovering certain constructs,are we simulating the intelligence of the creatures too?this wouldnt even be a game but a real evolution simulator.
If an environment selects a species for more intelligence you could get underwater species with the average IQ of 160 and then discovering such constructs is a piece of cake.What if we gave more time to squids and dolphins?They are already pretty close to us in terms of intelligence.
My opinion is that we shouldnt concern with the plausability of discovery of technology but if the technology is possible in that environment.
Was the metal smelting in vents debunked even if you consider the more malleable metals like tin???