work in progress: burl on the lathe - outside prep

I have managed to finish hollowing the vase or hollow form or whatever this burl is, and I have gotten the outside ready to finish. see it here
It introduces one of the questions that may hit several times as you turn a burl that allows a glimpse into the interior, "how much of the interior should be revealed and what do the edges of the opening look like?" A lot of the time the change from one thickness to another at the unsupported edge of the openings will allow a very thin membrane of wood to extend over the opening or negative space of the burl.

Those membranes can be left or removed. Each change alters the amount of light that enters the vessel along with varying shadows. The style of edge affects shadows and depth perceptions. How shall these things be done so as to leave the natural look of the burl but also expose its beauty to the viewer?

Hopefully I have begun to answer the questions.