Incorrect handling of PARAM_EXT_SET message for custom camera parameters

[kuroshZ]

Problem:

The PARAM_EXT_SET message (ID 323) uses a char[128] array for param_value, but its interpretation depends on MAV_PARAM_EXT_TYPE. Current implementation incorrectly treats all values as strings.
Example :

 auto command = message_set.create("PARAM_EXT_SET");
  float val = 30.0f;
  std::memcpy(&param_val, &val, sizeof(float));
  command.set({
      {"target_system", 0},
      {"target_component", MAV_COMP_ID_CAMERA},
      {"param_id", "YAW ANGLE"},
      {"param_value", val},
      {"param_type", MAV_PARAM_EXT_TYPE_REAL32},
  });
  fmt::print("command: {} \n ", command.toString());
  send_command(command);

Output:

 param_id: "YAW ANGLE"
  param_type: 9
  param_value: ""
  target_component: 100
  target_system: 0

The correct way of putting this message together is for example to use memcpy to copy the float value to the char array (example using c_library_v2 ):

void send_param_ext_sent()
    {
        mavlink_message_t msg;
        mavlink_param_ext_set_t param_ext;
        param_ext.target_system = 0;
        param_ext.target_component = MAV_COMP_ID_CAMERA;
        std::string param_id = "YAW ANGLE";
        std::copy(param_id.begin(), param_id.end(), param_ext.param_id);
        param_ext.param_id[param_id.size()] = '\0';

        float value = 60.0f;
        memcpy(param_ext.param_value, &value, sizeof(float));

        param_ext.param_type = MAV_PARAM_EXT_TYPE_REAL32;

        mavlink_msg_param_ext_set_encode(255, 0, &msg, &param_ext);
        uint8_t buffer[MAVLINK_MAX_PACKET_LEN];
        uint16_t len = mavlink_msg_to_send_buffer(buffer, &msg);

        asio::write(socket_, asio::buffer(buffer, len));
        fmt::print("Sent PARAM_EXT_SET\n");
    }

Question:

Is there a quick fix for this issue in the Message Object implementation, or is it possible to manually set the value as a workaround?