Corp Sprayer Servo Function 22

Hi im building a crop sprayer and i have noticed that my pump controller doesn’t work when I assigned the ServoX_Function to 22. and I also noticed that the function 22 is not there any more in the function list though its mentioned in the configuration documents and workarounds. But the Pump works when I set the servo function to 1 as RC pass through. But my issue is will the Rc pass thru can control the pump speed related to speed of the drone? How can i get the servo function 22?

Do you have found a solution to your problem ?
Because currently I have the same problem.

Thank you

What flight controller are you using? Some with limited memory have certain features unavailable.

I use the Pixhawk 3 Pro of Drotek

Im using cube black controller

No mate… still on the same but i haven’t tried it with mission planer if it works as servo function 22