Why would starting on any plane really matter?
In most cases the piece part is component of an assembly and designed in-context of other parts.
You allow the assembly to control the positioning of the component.
Now, I know from training in other systems (SW) that they stress working off of the pricipal planes for every part design. When I asked the instructor why they feel that way the only answer I got back was "How else do you design?" My answer was "in-context of an assembly where I can associate directly to the geometry in its assembled positions or from an absolute design position like auto or aero. What else is there?" The instructor looked at me funny and came back with "Well, we really stress bottom-up design." I laughed. Sorry, I'm just in one of "those moods" already today.