Syndrome- I honestly can't comment on the "source" because we have tested so many different compounds that I am not sure what the "source" is anymore. I can tell you that the tires that were run by FSEARA (Florida) teh pre-production blues on a prism wheel, are classififed as Jaco blues. Track temps were near 135 degrees and not 1 set that I saw suffered any of the blistering you describe.
Jaco will offer Green, Blue and Orange the corresponding or matching shore numbers are not known at this time.
Butter