Design Resolution: Dynamic Coordinate System

Does the design resolution of a Cocos2d-x application have to be a fixed size (hard coded)?

Is it common practice to use the device screen size as the design resolution (dynamic coordinate system)? How would it be done?

For example, some tutorials recommend setting the design resolution to 480 x 320 (a fixed size) and then scaling to the actual screen size. Can this be avoided?

I have a game that I am working on right now that uses what you all dynamic resolution.

My game gets the size of the screen and lays out assets in a custom layout that varies depending on screen size. So I don’t need to set the design resolution policy and size. So then the game uses the default, which is the devices screen size for the design resolution size and ResolutionPolicy::UNKNOWN.

Some other info here to be aware of: