This document is in great shape, and I do not see any missing operational considerations. Defaults are appropriately defined. I will note that there is a response at https://mailarchive.ietf.org/arch/msg/int-dir/zJ147M2VjQxTCOyRT7OQ42NYzco that states that additional figures are forthcoming. I think those will help (although I am biased as a visual person), and would encourage the new revision to be posted sooner rather than later. Thanks, -- Carlos.