Really confused about what they are attempting to test under the tabletop configuration.

It seems like their hypothesis needs to be tested in the middle of space away from the gravitational force of the sun and earth. If your calculations are off by a factor of 10^120, then making the test 1000 times more sensitive isn't going to help either.

Wouldn't scientists have had evidence of this being the case with the pioneer 11/10 anomaly? There was a slight deceleration that couldn't be accounted for, if dark energy was present in a vacuum wouldn't the pioneer probes (and the voyager probes now) show an acceleration that matches initial calculations?