Low speed ops with good reliable autopilots have been around since 1966 and they were NOT invented by the FRENCH.
Ah yes, Dodgy Doppler was great! Sea too calm - doesn't work. Sea too rough - doesn't work. Near a boat - doesn't work. Too far above the surface - doesn't work. Simplex system- doesn't work after a single failure. Overall it was fantastic!(not). Which might be why it would be a non-starter for routine CAT ops
Now triplexed inertial data, triplexed air data (all automatically selected in the event of failure), quadruplexed autopilot channels, duplex series actuators, now we are talking!
it automatically reverts to airspeed hold at Vy
Surely all modern helis do that!........... Don't they?