i'm writing this assuming you somewhat know how toaq phonology works. if you don't, check koitieq for an overview, and the delta refgram for the juice that i'll be getting into when we talk about coda [m].
so, toaq codas can have either no consonant at the end, [ŋ], or [m]. (a key difference between those two is that a long, initial vowel is always shortened before [ŋ], but before [m], it's still long. this will matter for later.)
[ŋ] in particular seems like it could just be phonologized under /n/ — after all, they never contrast. any word that has a [ŋ] after a vowel, actually has it after a glottal stop, as in [pulls random word from dictionary], nhuq'ao [ˈɲuŋʔaw] (soakue). so, you'd always know from an underlying /nan/ that it has to be [naŋ], because *[ŋaŋ], *[ŋan], etc are not possible. (alternatively, we could analyse [ŋ] as being /ɲ/.)
now let's get to my weird theory about [m]. the refgram has this to say about vowel length and coda [m]:
For example, nogı is pronounced [ˈnoː.gi], noqgı is pronounced [ˈnɔŋ.gi], and nomgı is pronounced [ˈnoːm.gi].
this implies that coda [m] is not like /n/ [ŋ], and also not like the glides that end diphthongs, since something like kaı is [ˈkaɪ̯], with a short vowel. (/ao/ is a special case, as in stressed syllables it can be disyllabic [aː.o]). and here is where i get silly and unserious — what if coda [m] is actually some sort of moraic nasal? a minor syllable of its own or whatever idk these terms?
if, say, nam 'bread' is actually /na.m/, then this explains why it gets realized with a long vowel, [naːm]! this would also explain the thing in the refgram about /m.m/ being realized as [mə.m], with an epenthetic schwa — it's because the first, coda /m/ is actually its own syllable!
this is like kinda serious but kind of also not serious. i came up with this theory with lanru's help; me and her have very unconventional theories about lojban phonology anyway..
comments agreements disagreements etc welcome. also cake i'd like some,