*Ground speed more than 40kts"
After further reading, this logic seems to apply only to test (but it's not clear if this is the CMC Test or the quick left/right confidence test during arming).
Thanks for the updates, guys
British Airways cockpit landing into foggy Gatwick - YouTube
Looking at this 777 autoland video, the PVD
inhibit during rollout only seems to operate with the A/P engaged (or are the F/D modes changed/erased when you disconnect the A/P?)