Michael, Currently, the new-portals system doesn't do this sort of auto-collapse/-expand of columns based on the position of the elements on the page, and I don't think it should. Users will be able to change the number of columns but _only if_ that's the action explicitly requested and only in the proper context. Why? Otherwise an ACES-like system that allows the number of columns to change "on-the-fly" would most likely break site designs that depend on a fixed number of columns. And I want to avoid conflating these two independent things (number of cols, and element arrangement) in the UI.
I hope that explanation helped somewhat. I plan to write up an detailed architecture guide for new-portals RSN...
