A two piece lever arm with four bolts and a keyway separate from the quadrant is considered good practice.
Allows for optimising the lever arm to the actuator stroke and the desired
rudder angle and gets the actuator off the same plane as the
steering cables which creates more mounting options in a limited space.
Also can provide a useful mounting point for a
rudder position
sensor
The quadrant may not be designed to take full load on a
single point where the actuator is attached.
Good luck