I'm not sure if its too late to say something(I never liked dead horses anyways). I'm also just a newbie who hasn't quite figured out what all is going on... but reading the thread I had a few thoughts after reading the thread.
Looking back I saw the talk about cloning and the nekos giving birth assexually. Given the talk of nanomachines this does make sense, but I also saw something about it being illegal for two nekos to be created the same?
Going off that string of logic, and the talk of a specific upgrade/injected program to allow reproduction, perhaps if the same upgrade allowed for the nanomachines to go through during the development process in the womb and change a few things around, a shade of haircolor there, maybe a few other small deviations here and there.
In the case of such an upgrade it could be turned off while the neko was serving in the military, and turned back on once they were out, so they could still do the self reproduction, but it would keep enlisted folk from needing to be taken off of duty for that.
And on the far extreme, given their computer-ish memory and their ability to access information from sources other than their memory... perhaps another advantage of the 29 could be that through updating from some source, give birth to later models than themselves.(That is of course, if there are versions beyond the 29.)
Just my two cents, my apologies if I don't make much sense. Overall I like the initial suggestions by Wes.