TL;DR: ges'njor' and g'jora as hyper-contracted forms of gesinjoro.
When creating a non-binary equivalent to sir/ma'am, we would prefer if:
- The word clearly evokes non-binarity as opposed to just gender neutrality.
- The word is not just a blend of masculine and feminine forms.
- The word is clearly understood in context as a term of address.
- The word comes across as having a real history, even if it really doesn't.
- The word looks and sounds nice and lacks any unintended negative connotations.
- The word is at most two syllables in length.
All the current proposals for a non-binary equivalent to sir/ma'am tend to fail at least a few of these criteria, but I figured that loaning from another language that's already created such a word could solve most of these issues. And that's when I remembered Esperanto gesinjoro, a back-formation from gesinjoroj ("ladies and gentlemen (and others)"), from sinjoroj ("sirs") + ge- (forms words of mixed, unspecified, or non-binary gender; from the German collective prefix, presumably motivated by its use in the German word for siblings).
An unadapted borrowing of gesinjoro would fill all but the last of my six criteria as long as you're in a crowd of samideanoj, which you will be some day, inshallah. In order to fill the last of my six criteria, then, we're gonna have to contract and contract and contract gesinjoro in the same way as senior → sir and mea domina → ma'am until we get a short enough word.
We begin with gesinjoro /ˌgɛsɪnˈjɔːɹow, ˌgej-/, matching the original Esperanto pronunciation as closely as possible; then we reduce all the vowels and delete the vowel before the stress, giving us ges'njora /gəˈsnjɚ.ə/. Then after this point we can take two paths: We can delete the final vowel, as is commonly done in Esperanto itself; or we can delete the vowel before the stress.
The first route gives us ges'njor' /gəˈsnjɚ/ as the final form of this word, which is what is rationally best. It remains recognizable enough to the original form, and I especially like how the beginning /gəs-/ sounds like the beginning of the Russian words for sir and ma'am, gospodín and gospozhá.
The second route gives us g'jora /ˈ(d)ʒɚ.ə/, which I kinda love just for how wacky it is, like deleting that one vowel forced a whole wave of sound changes for the sake of phonotactics. I'm listing /dʒ-/ as a variant pronunciation because I've known people who merge /ʒ/ into /dʒ/, and g'jora might give rise to a spelling pronunciation, anyways. There's not many words that start with /ʒ/, though!
Whether /ˈgsnjɚ.ə/ actually ends up becoming specifically /ˈʒɚ.ə/ for the sake of phonotactics kinda depends on the order of your constraints in optimality theory, though, so maybe your own surface realization has a marginal onset or deletes different consonants or whatever. For that matter you might not apply all the vowel reductions, or you might drop the /j/. All these variants can of course coexist, as can any number of variant spellings matching the different pronunciations. I went for the g'jora spelling just because I think it looks cool and that irregular spellings are neat sometimes.
As for those who might say that this is all pointless because we don't need honorifics to begin with: I just like making up words, OK?
Main for the main gods
Esperanto was cool for what it was trying to be at the time it was created. But the world moves on and now we're in a world where it looks silly and many of the decisions made in its creation look pointless.