These don't really fit into the Errata (one of these is probably a retcon) so here are two little nitpicky things that I noticed:
-Proyas' father's name seems to have changed, he is referred to as Onoyas in this book while before he was Eukernas II (admittedly, I had to look it up because I only knew it was different and didn't recall the actual previous name). Was this a retcon?
-Mimara's pregnancy only seems to have lasted for 6 months. I know, I know, I'm being annoying about timelines and dates again, but hear me out. When I first read TAE, I was wondering when Mimara would give birth (trying to figure out the length of time TUC would span). The chapter where she and Achamian have sex has a date of early spring, 4132. She ends up giving birth in early autumn of the same year.
You might say we don't know if seasons in Eärwa last 3 months,
but...in PON, Serwë got pregnant in the spring of 4111 and gave birth in winter of that year, thus it would seem seasons do indeed last ~3 months in Eärwa.
So either this is a timeline mistake (future retcon?) or that baby really lucked out in being continuously exposed to qirri while in the womb and came out with the development a full-term baby would have.

(Or, crackpot thought, Akka really isn't the father after all.)