PIO:s
The SAAB company took a patent may years ago on a method to prevent PIO (after the 2 JAS 39 Gripen PIO accidents), but normally this seems to be simply done by rate-limiting in the software. I don't know which method is used in the A330:ies.
I have been wondering if any such PIO-preventing function, which ought to be in operation in normal law, is still operational in alt law 2.
PIO can apparently also occur if the hydraulic system is overloaded by extensive control surface movements, especially shortly after a reduction in N1.
Keep up the interesting and good parts of the discussion.