^A couple thoughts along this line. She said there that her current 3000cc implants have a capacity to expand to 10,000cc, which to me means that they are less stretchy and probably more reliable for longevity. She has mentioned 10k as a goal, which at her current rate, could take many years; you can see that she made quick expansion almost monthly with her previous expanders but slowed to every 6 months on the new ones and those fills are not nearly as much as one might expect. From a device perspective, fewer accesses is smart and, IMHO, the ability to only add 300-500cc every 6 months may be reflective of Mary's undoubtedly very low body fat today; skin just doesn't have the stretch when so lean.
While no expert in the newer European expanders, I think Mary's are more designed for longevity over Foxy's. Think of it as beachballs vs balloons, both able to achieve a given circumference but thick vs thin. Which is why Foxy is concerned with attaining new ones, not only to go even bigger, but because she understands that she is in a precarious position.