> Adox have, no doubt, spent a very long time perfecting the film

No, Adox did nothin wit tha film CMS 20 is Agfa High Definition Pan, a very constraty working reproduction film (thought for b/w documents).

> No matter what developer and process you use, these films do not have long exposure scales

SPUR developer works at least satisfying. I used some rolls wit an older version of this stuff. The highlights were slightly too dense for my taste, but manageable.
I wrote a text in German. May be at least the images are of use for you: