Polish has a headstart thanks to our valiant SF writers. I'm surprised that *this* is one of maybe 2 of Dukaj's books that were translated to English, I'll have to check how did the translator deal with Gierosławski's internal monologue.
We have basically zero precedence for a grammatical regime in which an "I"-less speaker makes statements about itself without acknowledging the presence of a self. It just really has not come up