“Purity” is a really overloaded term here. There are vast set of material properties that simply don’t map to a definition “purity” as in some homogeneous concentration of a material. This is so early no one likely knows exactly what configuration of material to “purify” for the intended outcome.
There will likely be years of not decades of looking at differences in the materials and performance of related materials to more fully explore this discovery.
- purity as in the sample is uniformly constructed of the right atoms but they are not in the right configuration
vs
- purity as in the sample contains atoms that shouldn't be there in the first place
and finally
- purity as in: the sample that purportedly did show room temperature superconductivity turns out to be the impure one and that impurity is so poorly understood that we currently can not replicate it accurately, but a test by an independent lab of the sample would verify the properties as advertised.
All of these are possibles, and not mutually exclusive.
There will likely be years of not decades of looking at differences in the materials and performance of related materials to more fully explore this discovery.