tl;dr for language reasons Ninni is Nini in the Toki Pona translation. such a spelling change is consistent with the vanilla Toki Pona translation, but seems to be inconsistent with other languages' translations. should it be like that or should his name be spelled normally

"the vanilla Toki Pona translation" is actually the 1.19.2 toki pona translation and in newer versions everyone's name is spelled out completely. they even dropped the headnouns (except for C418 for some reason???)