I've been partial to superdeterminism for a long time, but I have no idea how one would go about testing it. In fact, it seems as unfalsifiable as many-worlds or other theories. Do you have a suggestion?
The kind of superdeterministic theories proposed by t'Hooft are falsifiable. From [0] "If engineers ever succeed in making such quantum computers, it seems to me that the CAT is falsified; no classical theory can explain quantum mechanics." By "such quantum computers" he means computers that can run Shor's algorithm. "...but factoring a number with millions of digits into its prime factors will not be possible – unless fundamentally improved classical algorithms turn out to exist."
As for the author of the article I've never seen a clear proposal but it appears the idea is to do repeated measurements that display quantum effects while reducing noise as much as possible and check if there are deviations from quantum theory.
My understanding was that many-worlds could be tested experimentally if we were able to set up large objects in superpositions, and I thought that there is no reason to expect that it isn’t physically possible to do so (we just don’t know how at the moment).
You can’t get any information from that because the main interpretations all make the same predictions from an outside perspective, which is what you’ll expect to see.
Besides to put a person in a superposition may require a machine as large as the universe, so you get issues with the speed of light.
The only way to test MWI is multiverse immortality - many worlds means you should expect to always have some future experience - there is no real death.
Hossenfelder proposes[1] to measure non-commuting variables in identical systems in as noise-free an environment as possible.
In standard QM says the measurements should be completely uncorrelated, but she argues that in a superdeterministic theory results somewhat correlated.
