The document is written in a clear and concise manner. 
The authors have done an excellent job of making a difficult subject clear and readable. 

Two technical sections should be checked against implementations of IS-IS with dense flooding (section 6.6.2.1 and section 6.6.2.2.  I am not implementing so this check is beyond my capabilities. 

Editorial nit:  
section 3, requirement 3, sentence 2.  "Just addressing a complete bipartite topology such as K5, 8 is insufficient."  An informative reference to K5,8 or a bipartite topology might be helpful to readers.  This is an optional editorial comment.