28 Dec 2018, 00:28
Lags are built into the surface command paths for all surfaces at all speeds and altitudes. The purpose is to make the airplane very responsive without being jerky with overshoot and oscillations. The lags are different at different flight conditions, not just more supersonic lag. Many filters are also in the control paths. The control stick force command to g or roll rate command are non-linear, again to obtain smooth accurate maneuvering, while still maintaining rapid abrupt maneuvers when desired.
This is only a very rough description of how flight controls can be tuned to obtain desired characteristics. The task is enormously complex, difficult, and costly. The people who do it are magicians.