But was it the clock or was it the gravitational field? The clock is still a material entity, something that can never be denied. We cannot measure time in distinct locations without also having a material ‘reader’ present.
Same question said differently, if we keep the ‘reader’ out there twenty-five times as long as the classic experiment, will the new result distinguish time also twenty-five times longer than the classic test.
If not, then we know it is the medium and not space-time. Did we pursue checking the fallibility of the test?