The above is merely the CMC’s interpolation via the Rotation Rate.
if you keep feeding the character a location to move to, they will use this value. Technically speaking, no actual turning script is needed here. But we, obviously, have very little control over any nuances. You can turn those nav mesh points into a spline, and sample direction as you slide a dummy along it. Makes it pretty smooth.
The feel the real questions here is:
How playable is it? How manual is turning suppose to be?