The issue here is whether it is better to augment YANG library or define a new version of YANG library. The conclusion of this issue would seemingly depend on what the nature and scope of the changes to YANG library is. If the majority of the changes can be defined in a separate YANG packages top level object, that augmentations to YANG library would seem to be the most suitable approach.
Closely related to #10.
The issue here is whether it is better to augment YANG library or define a new version of YANG library. The conclusion of this issue would seemingly depend on what the nature and scope of the changes to YANG library is. If the majority of the changes can be defined in a separate YANG packages top level object, that augmentations to YANG library would seem to be the most suitable approach.