I recall that there was a similar experiment conducted during the 1970′s in the Interlake region of Manitoba, Canada. The one obvious negative effect of this was a significant drop in labour participation rates among three groups; youths, women with children, and near-seniors.
The experiment wasn’t even set up in such as a way as to expose the worst outcomes. Such a test would have to restrict the taxes needed to pay for the Guaranteed Basic Income to the same geographic area as the available benefits; allow benefits to those moving to that area; and run for two or three generations.
Experiments with falling objects, from the time of Galileo onwards, demonstrated that objects of differing weight, but the same shape and density, did indeed fall at about the same rate. Also objects of the same weight, but differing shapes and/or densities fell at different rates; thus strongly supporting the hypothesis that the differences in rates of falling were due solely to air resistance. The later experiments, conducted in vacuum, simply confirmed beyond reasonable doubt this hypothesis.