I think we should remove the NPY_RELAXED_STRIDES=0 compilation option. It has been many years that 1 was the default and it adds a bit of cruft in places.
Probably, should be done after branching NumPy 1.22. But that is (as of writing) just a few weeks away.

Personally, I am not worried about this breaking anyone. Relying on relaxed-strides to be disabled, would mean you are compiling NumPy yourself just to avoid fixing a pretty simple issue.