Keep the updates coming Pierre! Looks great!
btw, what will you do with the center post? Will it just be a beam, or will you finish that too?
I think you may be talking about the temporary 2"x6" shoring post. It will be removed as soon as the engineering around the stair is finished. I will also be extending the center post (of the staircase) to the ceiling to anchor the railing along the edge of the loft floor. I am engineering as I go.
There will be a bedroom under the skylight with a 3' balcony for access. (See the pano and imagine that the curved edge of the loft framing is straight.) The railing along that edge will support the loft floor. It will probably be a truss resting on the center column of the spiral, and a yet to be built pony wall at the jog, with support in the middle provided by a tension member coming down from the peak of the roof. At the right end of the balcony, (where the edge jogs back) a stair will go up over the beam and lead to a door of some sort in the roof leading to a rooftop deck.
I have until Christmas to finish the whole project. Believe it or not, there are two tenants occupying the space. Everything gets built in my shop elsewhere on the property, and screwed in place when the tenants are at work.