James Webb Space Telescope finds evidence for alternate theory of gravity

I follow the lead author, Stacy McGaugh, via his blog where he posts discussions and musings about the latest research into the dark matter vs MOND debate: https://tritonstation.com/new-blog-page/

His arguments are very convincing and relatively clear. I am not an astrophysicist but I have two degrees in physics and have always found the dark matter theory to be lacking -- in absence of any evidence of causation whatsoever, dark matter can only be described trivially as "where we would put matter if we could to make our theory of gravity make sense," which is totally backwards from a basic scientific perspective.

Predictions based on modern MOND postulates are shown to be more and more accurate as our observational instruments continue to improve in sensitivity.

I don’t think that’s quite fair. That approach is exactly how we find planets. Here’s an unexpected variance in the motion of a planet or star. It could be explained by a planet over there. Oh look, there’s a planet over there.

Hypothesizing that a planet might be over there is a testable hypothesis.

Have we found a way to verify the presence of dark matter yet? Or is it still an untestable hypothesis sprinkled around distant galaxies so their acceleration curves look right?