Interesting. I think OpenAI here uses sparse autoencoders to map out sparse activation patterns in networks. Comparing them to how a real person reasons about a situations.
Inspectus, on the other hand is a general tool to visualize how transformer models pay attention to different parts of the data they process.
That OpenAI work is more elaborate. It trains an additional network in such a way that it encodes what GPT is doing in terms of activations, but in a more interpretable way (hopefully). Here, as far as I can tell, it's visualizing the activation of the attention layers directly.
Inspectus, on the other hand is a general tool to visualize how transformer models pay attention to different parts of the data they process.