GrayRhino,
I hope this comes across right....
Everyone has their 'perfect shot position' for their perfect shot that is the main shot we practice with. Everything is level, balanced, and wonderful.....
Then we enter the woods, and we aren't guaranteed that perfect shot....the terrain and game dictate, and we must adapt.
Therefore, that's why I always say that form is from the waist up. If you have the 'magic T', you can take that normal perfect shot with you by bending at the waist for different cant angles, uphill or downhill, or rotating left or right.
So, 'open stance' or 'closed stance' to ME is a personal preference, and a comfortable position for the 'perfect shot position' that we practice and always wish we could have in the woods.