@io One more crucial detail about these dial menus is that they easily allow the options to change, and it's easy to stack them (one radial dial option replaces the current one with a more specific set of options) to provide a hierarchy of contextual actions. They're pretty slick, which is why I think they'll become more prevalent over time.
If you have more or fewer options at any given time, then you just add more subdivisions. I don't know the details but it's not jarring when they change.