[ⁿdzɿ˧˩wɒ̃˩], [a ɒ e ə o i u ɿ v̩] <a q e z o i u y v>; <z> in the onset is [dz] (this isn't ambiguous because strict CV syllable structure) and doubling the voiced letter gets you the prenasalized one. The orthography is phonetic rather than phonemic because phonemic analysis is hard, and the prestige dialect has restructured itself in a manner conducive to a four-vowel analysis, with /a ə ɿ v̩/ and maximum C(j|w)V syllable structure: /a ə/ [ɒ o] after a labial and [æ e] after a palatal, /ɿ v̩/ [i u] after a semivowel. So the name of the language could be phonemicized /ni˧˩wã˩/.
However, the language above is not Zzyxwqnp, but Zot. (They call themselves Wedenf /weðe˧˩/; Zot is an exonym, and an obviously un-Zzyxwqnp one, so it's probably either from Kangshi or Narng.) An important difference between the two is that the syllable tone system of standard Zzyxwqnp has not yet degenerated into a word tone system, as it has in typical Vengic tone languages like Zot, so a tone letter is needed on every syllable.
Since Zzyxwqnp is the prestige language of the area in which Zot is spoken, I figure Zot should be romanized with an adaptation of the Zzyxwqnp romanization; cf. Chinese minority languages with their weird adaptations of Pinyin. But so far Zot is the only Vengic language phonologically close enough to Zzyxwqnp to do this to - I've of course made all the conservative languages first, and they haven't lost their coda consonants yet. (What, which is probably the one in my sig, has coda consonants and tone letters, but it only has two tones, written zero and <h>; it also doesn't allow open stressed syllables, so coda /h/ is unwritten, but coda /h/ only shows up before a pause or in reduplicated forms.)