That domain knowledge wouldn't have suggested exploring this space for superconductivity.
Turn the material science problem around: instead of looking for a substance that has a specific property, look at many substances until small amounts of any interesting property (young's modulus, etc) show up. By looking for "anything interesting" you are more likely to find something of interesting (ideally, several somethings). And then you also know a starting place to begin optimiziation.
(I'm not saying these things out of ignorance; this technique has worked well for me at times when I had exceptionally large amounts of CPU available to me, and it's also worked well in the drug industry, which has similar problems to material science.)
I think the first insight to pursue LK-99 by the researchers was from the deceased scholar from their graduate school (department chair I believe?). The material was already found in 1999, but they need to try different synthesis methods over 1,000 times for slightly different chemical compositions. I am not sure if there are simulation methods to do that, but it was definitely theoretical insight that first convinced their teacher to start, and the work made the pupils to believe in what they are pursing as far as apparent background stories are concerned.
Turn the material science problem around: instead of looking for a substance that has a specific property, look at many substances until small amounts of any interesting property (young's modulus, etc) show up. By looking for "anything interesting" you are more likely to find something of interesting (ideally, several somethings). And then you also know a starting place to begin optimiziation.
(I'm not saying these things out of ignorance; this technique has worked well for me at times when I had exceptionally large amounts of CPU available to me, and it's also worked well in the drug industry, which has similar problems to material science.)