I get the impression that physicists who advocate “superdeterminism” are ignorant of the philosophical literature on “determinism” - because from a philosophical viewpoint, there is nothing “super-“ about their position, it is just plain old “determinism”.

Advocates of superdeterminism aren't always in favour of the term. Its most notable advocate, Hossenfelder, disapproves of the term, believing it to be misleading. She suggests the term 'implicate order' (crediting Bohm) be used instead.

Exactly. Even if you dispense with hard determinism and allow randomness in your theory, pure randomness is not really free will.

Free will is also incoherent in any religion or philosophy presupposing a bi-omni deity (which itself is an incoherent notion).

The point, that many ignore, however is that, free will does not matter. It is irrelevant. Regardless of whether one has free will or not, one still has to make choices and support the consequences of said choices. Lack of free will was never the get out of jail free card some fear it to be.

If you bring in to the discussion sociology and psychology, free will makes even less sense.