SimpleTransmission and dynamixel_hardware

[gpicardi]

Hi everyone,
I am trying to set up the transmission mechanism to work with my dynamixel-based manipulator. Of course I am using this plugin for the hardware. I am using humble on Ubuntu 22.04.

I have a 3 Dof manipulator with forward position controller and joint trajectory controller. Both using a position interface. I want to add a transmission element on the tibia joint (a SimpleTrasmission now for simplicity). The only modification that I have made is in the ros2_control tag in the urdf, in which I have added the following block:

<transmission name="tibia_transmission">
      <plugin>transmission_interface/SimpleTransmission</plugin>
      <actuator name="tibia_actuator" role="tibia_actuator">
      </actuator>
      <joint name="tibia_joint" role="tibia_joint">
            <hardwareInterface>hardware_interface/PositionJointInterface</hardwareInterface>
            <mechanicalReduction>40.0</mechanicalReduction>
       </joint>
</transmission>

I have tried different modifications of this snippet ( instead of , hardware_interface instead of hardwareInterface, mechanical_reduction instead of mechanical_reduction, EffortJointInterface instead of PositionJointInterface). Everything loads smoothly, but the system is simply ignoring the mechanical reduction. My question is, should I modify the dynamixel_hardware plugin?

I am also reporting the yaml file of control.

controller_manager:
  ros__parameters:
    update_rate: 30
    #use_sim_time: true

    joint_state_broadcaster:
      type: joint_state_broadcaster/JointStateBroadcaster

    forward_position_controller:
      type: forward_command_controller/ForwardCommandController

    joint_trajectory_position_controller:
      type: joint_trajectory_controller/JointTrajectoryController

forward_position_controller:
  ros__parameters:
    joints:
      - coxa_joint
      - femur_joint
      - tibia_joint
    interface_name: position

joint_trajectory_position_controller:
  ros__parameters:
    joints:
      - coxa_joint
      - femur_joint
      - tibia_joint

    command_interfaces:
      - position

    state_interfaces:
      - position
      #- velocity
      #- effort

    action_monitor_rate: 20.0 # Defaults to 20

    allow_partial_joints_goal: false # Defaults to false
    open_loop_control: true
    allow_integration_in_goal_trajectories: true
    constraints:
      stopped_velocity_tolerance: 0.01 # Defaults to 0.01
      goal_time: 0.0 # Defaults to 0.0 (start immediately)