Real question, has anyone actually developed an attack that could be executed? I know “what it would look like” is easy to explain, but is there any implementation?

I’m not sure we’re super susceptible to an attack. Assuming you could spot an attack on the network post-hoc (anyone can read the blockchain), if an attack occurred it would destroy the value of bitcoin. This would probably destroy the value of the attackers coins and the attackers mining rigs… which seems like a net loss.