I find the taps very helpful for in-car navigation, since I can feel the taps and remember to get over for a turn (at a comfortable time) even if I'm deep in conversation.
But, like you, I'd like more control on how and when the map app appears on my watch at differing times.
For myself, when I'm in the car and listening to an audio book I need the now playing app visible on my watch at all times. It gives me much better control over skipping back in the audio book than my car's steering wheel and console controls. I'd personally like a setting option that offers haptic taps for upcoming turns on my watch, without the maps DISPLAY on my watch, so that I always have access to the watches now-playing app. Maps replaces now-playing whenever it shows me a turn, and stays there.
I'd like both of our requests satisfied.