I think you got it right Tony.

I also think that bureaucratic dictates are cyclic, tend to fade and get resurrected periodically, which would explain the inconsistent demand for the evaluation.

As I no longer teach, nor am subject the needs of employment, I can offer this advice to individuals:

Resist taking the evaluation as it is flawed, inaccurate and subject to interpretation with Chinese characteristics. If you must take the eval then you must. A clever person can figure out how to preview the test before doing it live. After you do it, complain about the spelling errors, undecipherable questions, and the vague results. Be sure to always maintain a harmonious spirit!

I actually tried taking it when my school asked me to. There were a couple of questions I couldn't for the life of me figure out why they wanted (some personal non-relevant stuff too) so I sent a mail asking into them. Never heard back, also the 'online interview' never worked. Now, this was in the beginning of the implementation of this brilliant idea so I assume they've bettered it by now, although knowing China I wouldn't put money on it. Long story short, I never finished it and I renewed my contract twice after that with no problems at all. Still got my Z and Foreign Expert Certificate. I believe we were 9 or 10 foreign teachers at my school at the time and only 3 or so managed to get it done. The school never heard back as far as I know on the missing tests -or whatever they are.