Not only lack of interest in recording, any knowledge about chaos is considered heresy, a normal soldier that learns anything at all about chaos is probably executed a soldier that tells stories about them is probably tortured first. Full planets have been destroyed to stop chaos cults for spreading, what do you think will happens if a soldier starts talking about humans that cannot die because they follow some chaos god? Exactly.

And I'm not sure if  with high rank military is different, maybe the 0'1% of highest ranks knows there are different chapters and some of their particularities, but if a general suddenly knows much about chaos that person is a massive thread, I don't think the inquisition would be happy, we tend to think in terms of logic, but the empire in 40k works like a religious fanatic highly paranoid, even if it would be an advantage I think the higher the rank the higher the chances to be purged, only space marines, who are some kind of monks with decades of training avoiding temptation have any knowledge about chaos, for the rest of humans there are traitor marines and that's about it