Fits 1, 2, and 3 are completely new lasts. Vapor lasts from before don’t correspond to the new system. There have been quite a few people on here posting that they don’t fit any of the new fit numbers as well as they did their old Vapors.
I think some confusion comes from Bauer’s old 3 fits—Vapor, Supreme, and Nexus, and a lot of people thinking those were now renamed 1, 2, and 3. That would allow you to get a Vapor built on a Supreme or Nexus last, or a Supreme built on a Vapor or Nexus last, as well as their ‘native’ lasts, but instead Bauer created 3 new fits to best suit the data they collected with their 3D foot scanning app.