Would holding various bb poses for X-amount of time with moderate to high intensity, help with definition?

I think it definitely helps with muscle separation and control.

yes, it definately will help. when prepping for a contest, ill pose for 30-40 minutes straight. its a great workout in itself. ill be drenched in sweat and i even get sore (especially shoulders) from posing. its also good to do because the practice makes it a natural thing to flex all your muscles in each pose and this is very important onstage.