AUX Failsafe

Dear all,
maybe someone can help: I am operating a copter with CubePilot/Herelink system. I have a payload which I would like to disable if entering failsafe condition. The payload can be switch on and off via relay which is connected to AUX5.
Now, I did not find any hint in the documentation that the AUX channels have a failsafe setpoint. My objective would be that the AUX5 switches off once failsafe condition occurs.
Any ideas?
cheers Patric

You should be able to do that with LUA scripting
Check for failsafe status, change a servo (aux) output