However, in both of those studies, participants wore their under-corrective glasses continually, regardless of whether they were doing near-work or just walking / looking at a distance. This is a crucial error, as pointed out by at least Hung and Ciuffreda: <https://www.oepf.org/sites/default/files/journals/jbo-volume...>. It makes intuitive sense to me that under-corrective or anti-corrective glasses should only be worn for a limited amount of time each time and only when doing near-work, in order to induce temporary pressure that the (feedback systems of the) eye can then attempt to correct.
Also see this 2009 review by Barrett regarding the more general practice of behavioral vision therapy: <https://doi.org/10.1111/j.1475-1313.2008.00607.x>. Behavioural vision therapy is a wider term, referring not only to the effort to slow myopia, but also to correct other vision problems through changes in behaviour.
