I would love the ability to Sort within Timeline view. Having the two groups is not enough and with no sorting ability, it really limits the effectiveness of the information I am trying to show. For example, I may want to to see the projects that are being worked on. I would group by Resource, then Project Category, but then maybe I want to sort to by size of the project.
Currently, I would have to use a parent row to act as another grouping, but this adds unnecessary clutter to something that is supposed to be visually easy to digest.