Those are pretty interesting concepts. I liked the one ( I don't mean to pick favorites ) because the original coverstone came in many circular pieces and a center piece, which resembles the iris. I always wondered how they were able to have the iris closed and not disintegrated by the vortex. I theorized it was because it was close enough to prevent it from coming out and the vortex spread across the iris, which makes a loud noise because it's trying to expand. I had a theory I wanted checked out. I think the vortex expands like that because of unequalized pressure at the beginning which eventually equals out and seals it at the gate. Like an underwater cave. This may be caused by too much power ( a design flaw ? ) because when Thor, Cassandra, and Lya opened the gate ( hand device may use less power ) it just spread in a circle and remained stable. I also think there may be a wormhole always open but it's not always there.