[TheMechanist]

Given that the AMD Ryzen 9 5950X can compute around 28.1 million SHA-256 hashes per second, the time required to calculate the hash of such a proposition including all possible 9-length hexadecimal strings to would be approximately: 68.72 x 10^9 strings/ 28.1 x 10^6 hashes per second ~= 2450 seconds. The hash starts with 0 so the calculation would have been much shorter i.e. just around 2 minutes. This can probably be explained in terms of the birthday collision problem.

[dooglius]

I don't think anything about birthday collision is relevant here, having a collision doesn't help in this scenario.