As admirable as these pictures are, I cannot help but think they would be much happier with a internal bra that would hold them higher (at a height determined by themselves and the surgeon), thus be far more manageable by a posture change that negates the weight to a large degree. Of course, the trade-off is that they would then be higher and create more big boob moments, when your boobs effectively get in the way as you reach for things or affect your line of sight, but I view these things as a positive to any girl that loves having huge boobs.
The internal bra for natural large breasts is something offered throughout Europe. There was a particular supplier/pioneer that first introduced it in London in 2014, and the website had dozens of places performing the procedure in Europe last year, but the actual name escapes me right now. In any event, it involves using a mesh, much like for implants, that is inserted below the skin on the underside of the breast, that is then attached with braided suture to titanium screws into bone structure, typically the 1st rib medially and laterally, however, for really heavy breasts, to the anterior shoulder. Unlike the mesh used for implants, this mesh is much cheaper, thus the procedure cost far less. It is preformed on a outpatient basis and if I remember right, the cost in London was <$3000.
I found these sites that explain the procedure
https://www.foxnews.com/health/controversial-internal-bra-procedure-promises-a-longer-lasting-breast-lift and
https://www.kaoplasticsurgery.com/procedure/internal-bra-mastopexy/ for smaller breasts (no braided suture support). The strattice referred to in the news article is the expensive stuff (like $6000), while the European version uses surgical silicone. As you can imagine, the height and the shape can be determined according to the patient's wishes in many cases without additional surgery and it is essentially permanent. Of course, with huge natural breasts, like those pictured, the result would be that they are now being supported as if they were wearing a bra, however, in the absence of said bra, all the boob jiggle and sway would still be presents. A win-win.