While looking at our __array_ufunc__ implementation, I noticed that it looks on all args and any kwargs['out'] entry. This is OK for the regular ufunc.__call__, but for the other methods, it means that if you pass in, e.g., an axis as a positional argument with something that overrides __array_ufunc__, it is counted, and you get your override. This is probably not intended, if only because it means positional and keyword arguments are treated differently...

Unlike the other issues, probably a bit less critical, but still, should be fixed.