I am not sure is this helpful. From the example, you probably can design a state machine (local variable) and using update to callback to next state (action). Just my quick idea, never try that before. Probably you may need to design RC11 edge trigger detection to start the state machine instead of read RC11 value.
return update, RUN_INTERVAL_MS
Careful not to overload the flight controller unit until no processing time sufficient for the core operation (flying, position holding, etc).