[Unanswered]  X', Qc' and Ev' tip's materials

Does anyone know what exactly are materials used for different rubber drivers' tips? I once browsed some online shop which was selling Corocoro exclusives where materials for every part of product were also specified. It was stated there that both Jl' (Royal King Spriggan) and V (Zillion Zeus Golden God) use polyvinyl chloride which confused me since difference in hardness of rubber on Jolt' and Variable is obv quite significant. It also said that Unite, Xtreme' and ßite also use the same kind of rubber which was identified as 'styrene-based elastomer' - pretty much the same case as above. Moreover, Google search about styrene-based elastomers (SBE) and possible ways to control their properties had 0 success. Can anyone tell me if there're any easy ways of purchasing some SBE materials in any form and easy ways to change hardness/flexibility of both SBE and PVC? I just want to make DIY X' rubber tips too much lol
I suspect the rubber parts of Beyblades are molded rather than cut and for most synthetic rubbers, including styrene-butadeine, that means a lot of unpleasant chemicals as well as vulcanisation so it's not a home-friendly process. It is possible with could be done by cutting a block (which seems a little hard to find for the specific materials, and will have varying hardness), but it would be difficult to get it right...