According to YM reader Phil Ball:
There's no need for a CEVNI as far as Dinan (effectively all of it) on the Rance.
Also no need for a CEVNI on the Canal de Caen a La Mer as as far as Bassin Saint-Pierre Marina in Caen.
So 10/10 to Phill Ball for checking.
PS: Anyone aware of a response to Kieran Flatt's article last week?