I wonder how the radiation affects things like ESC motor timing, communication protocols, the cou inside the drone flight computer etc.
But also lots of things don't matter. Like if your ESC hiccups for a millisecond or gives a blip too much power no one cares because there are no long term consequences. Like the extra noise in the video feed, ok it's there but of no actual consequence.
The important parts are long term stored variables and ensuring that state is maintained or can recover.
The surface area of things that really matter which are vulnerable to radiation is really quite small, the rest has either 0 effect or manifests as very survivable noise.
Source: ran the flight computer team on a student satellite competition long ago.
I don't remember all of the details of the OS level things we didn't have control of for the different OS options out there, we were just going to use Linux though, it was a viable option. One of the things you do is have a really simple hardware watchdog which will just reboot everything if it stops receiving the right health indications for exactly the case of difficult to recover faults.