Nit: it's possible that there is a finite number of Pareto optimal sorting algorithms, and it may be possible to enumerate those.
Procedures that enumerate Turing machines are generally very easy, or nigh impossible
O(n log n) is only the frontier for comparison based sorts that know nothing about the distribution of inputs.
If your sorting algorithm is allowed to do anything else on your data, like hashing or looking at bits or arithmetic, different lower bounds might apply.