How to handle async calls by using Flutter Riverpod StateNotifier

Question

Which of the following ways is the proper approach to handle async calls using Riverpod in Flutter? Should I worry about the getStringResult asynchronous call when the controller is being disposed as I do in approach B? Or shouldn't worry about the async call, can I use the simple approach A?

Approach 'A'

class Controller extends StateNotifier<String> {
    final Repository repository;
    
    Controller(this.repository):super(null);
    
    startAsyncJob() async {
        state = await repository.getStringResult()
    }
}

Approach 'B' by using the StreamSubscription

class Controller extends StateNotifier<String> {
    final Repository repository;
    StreamSubsciption? sub;

    Controller(this.repository):super(null);
    
    startAsyncJob {
        sub?.cancel();
        sub = repository.getStringResult().asStream().listen(event) {
            state = event;
        });
    }

    @override
    dispose() {
        sub?.cancel()
        super.dispose()
    }
}

I am using Approach 'B' in my controllers but it seems overkill to me. Did I overthink the problem? Will the async calls be disposed automatically when the controller does dispose?