In my experience, when I've been an observer in my dream, I can rarely take direct control. I may have some influence -- maybe.
My most lucid dreams have been first person.
I will also have very immersive dreams, and sometimes even realize they are dreams, in which I can sense everything as if I were there either realistically or in some exaggerated fashion. Sometimes I realize it is a dream, and still even in first person, I a merely an observer along for the ride.
If I try too hard to take control in a dream, it can wake me up.
I know it's not much help. I'm not an active lucid dreamer; I have some lucid dreams, but it is not something I try to do.