That might be an idea, although it's a costly one 😐
I might have to do that already to get the wheels I want, since, for example, VOLK TE37V have Japanese certifications that have higher demands than the German stuff, but they don't do some salt-test which apparently can't be done on its own.
So, unless I find someone saying something different, that'd be buying a wheel, and having it tested DESTRUCTIVELY.
Currently my two favorite options are either that Skyline-Brake (but I'll wait and watch if the guy doing it gets it TÜVed), or Wilwoods all around.
Which I've seen getting TÜV TWICE now.
Max