Some aircraft may require 'follow through' from certification.
e.g. autopilot runaway above 1000 ft may use a 4 sec reaction time. Below 1000 ft, 2 sec could apply providing the pilots is 'hands on' to reduce height loss, quicker reaction.
jimtx, if you imply that you are over-riding the autopilot - applying force other than that from the AP, then be prepared for a surprise: - back driven trim, sudden force disconnect.