Maybe, but careful reading of tips now brings me to this:<pre>
Words starting with a vowel Words that start with a vowel do not technically undergo eclipsis, but they do get the letter n- added to them wherever other words would be eclipsed — unless they come after a word that finishes with the letter n. A dash is placed between the letter n and the vowel — unless that vowel is a capital letter.</pre>
They don't write anything about n with dash in case of consonants...
Exactly so. We were mistaken in confusing what they call "the n-prefix" with Eclipsis, which always applies to nouns beginning with a consonant that is liable to be eclipted ('d' is one such), in a situation where it ought to do (plural possessive is one such). So "n" is here the "n" of the eclipsis, not the "n" ("n-") that precedes nouns beginning with a vowel when used with plural possessives.