At first this new type of source roots is added to Java projects only. I don't think Flash modules need resource roots because resource files in Flash modules are handled in a different way than in Java. Default setting is 'copy all files from source folders (except *.as and *.mxml) to the output folder'. So in Flash module you can have a separate 'resources' folder with resource files marked as a standard source root and it will be handled excactly in the same way as this new 'resource root' in Java.
At first this new type of source roots is added to Java projects only.
I don't think Flash modules need resource roots because resource files in Flash modules are handled in a different way than in Java. Default setting is 'copy all files from source folders (except *.as and *.mxml) to the output folder'. So in Flash module you can have a separate 'resources' folder with resource files marked as a standard source root and it will be handled excactly in the same way as this new 'resource root' in Java.