The OS plane will be used for that. The other two probably won't.
The DME is an inherent part of the system. It will be used for "everything".
This comment seems misleading since we know why devs utilize things like dynamic and/or adjusted res. It's usually in a game that needs every ounce of graphics power squeezed out of it in the first place. The display planes are there to help give devs more control over resource management. And if you read the background/summary of the patent it is pretty clear their goal is absolutely to offer QoS guarantees based on saving resources. I would also disagree with your suggestion that dynamic res/fps/etc isn't to be considered a component of optimization.
Where dynamic resolution is concerned, the QoS is guaranteed by sacrificing something, as the patent put it. I didn't say it's not a component of optimization. I pointed out there are other software optimization techniques developers may use to avoid sacrifices in a standalone game. The developers will/should focus on those techniques first.
The display planes are helpful in compositing (for free). But within a game, I doubt the saving is great. They can control the update rate, timing, quality, quantity, and region of different elements by software.
It seems that the display planes are more useful and their benefits more apparent when you have layers of information from different sources. e.g., Custom software HUD over a dedicated video decoder output, OS mouse cursor over an app window, miniaturized game output in OS screen, AR over Kinect video or Blu-ray. It may mean Durango can compose all the different output together while ensuring the responsiveness of the OS. These are part of the "new" experiences I expect in the Durango OS.
But it costs resources to do it via software...moreso than it would on Durango's setup, no?
Yes, but how resource intensive is the final compositing for a game ? The GPU is very efficient at pixel operations, especially when all the in-game visual elements are generated by it. The programmer has full control over what not to draw, and how frequently to draw the visible ones.
As others have pointed out, without the display planes, it is not uncommon to have color conversion, scaling, compositing done as part of the display engine too (Many have simple hardware overlays to do this). The Durango display planes seem more elaborate in that you can divide them into 4 quadrants to mask obscured output. As such, they may be there because Durango's OS relies on them for a new and consistent experience.