Bowl Blending

Gents,
i'm currently porting, gasket matching, bowl blending my head, and still am not 100% sure how far to go in the bowls. And i cannot tell by any picture i've seen simply because i think it's a difficult thing to photograph. so, is the goal to remove all the casted material within the tube so the valve essentially comes out of the smoothed wall of the port? i've attached a sketch which shows the original vs, what the completely smoothed tube would look like in case that helps clarify the question. any thoughts?

jp