Authors of the IG and CQI workgroup were seeking comments from community with respect to 

1.  Composite measures
   N/A
2. MeasureImprovementNotation
   Adding a 'reference range' code to the code system and value set are fine though questionable if the improvement notation being provided is not actually a range, but text.

I think the better approach for handling the related reference range would be to provide an extension (in addition to the 'reference range' code) that allowed the range to be discretely defined as a lower and upper bound. After all, that is a reference range. If that does not meet the use case or narrative explanation of the range is needed, perhaps the extension could have an option to provide just the range, the description or both. This latter approach would seem more flexible and allow for scalability for those measures that knew the range. In cases where the range could not be easily defined, just the narrative could be provided.

With respect to the narrative, I would recommend adding an extension to improvement notation. Requiring the improvement notation narrative to be put in Guidance or the Rate Aggregation narrative seems unrelated to the actual improvement notation. This would also better align with an authoring UI where a text box could be presented to a user who selected an improvement notation value of 'reference range' rather than making the author remember that narrative needed to be stuck in Guidance or a Rate Aggregation description.