MAVLink, PX4, QGC, Arduino RC cahannel Override, Mission

Hello,

I am new, in MAVLink message routing. I am trying to send RC override message to Pixhawk-PX4 via Arduino. Before this I have tasted the message in Ardupilot in Mission Planner, I used a basic sonar sensor with arduino and tried to change the pitch with the value of that sensor using this message-- mavlink_msg_rc_channels_override_pack(255, 0 , &msg, 1, 0, R, P, 0, 0, 0, 0, 0, 0), and the command was working fine, also I can see the radio value changing as the mapped value in arduino . It was mavlink version 1. And then I tasted that command using MAVLink 2 message mavlink_msg_rc_channels_override_pack(255, 0 , &msg, 1, 0, R, P, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0); using QGC on Pixhawk-PX4. But I couldn’t see any change in QGC radio data. The harware system was same. Most probably am doing wrong in the ID management. Here we are using system_id, component_id, target_system, target_component. (1)Which valuse i should use in this four parameter? And other hand, Actually I am trying to do override path change during mission. so (2)is it will be a good idea to use RC override during mission? I am asking because if i use RC override then the original remote will not work untill the sensor work finish, and anyhow if the sensor fails vehicle can be crashed. So (3) is there any other messaging method for mission override, where i can override that with RC if i need?
I am tring to send msg— Sensor Value>Arduino>MAVLink message(RC override/Mission Override)>Pixhawk-PX4
If anything wrong in my understanding please tell that too.

Thanks