On NixOS in particular, unless it's something so esoteric that I know it's worth documenting (or so obscure that it's pointless to remember), things tend to be pretty self-descriptive and most changes are relatively small.

I mostly just check the diff, and if nothing looks particularly wrong, I commit it. I mostly care about the final result. Commits are there for eventual auditing, but they're not that important to me.

I (or an LLM) can always clean things up later, and there's plenty of time considering this is the configuration for however many machines I'll be using for the foreseeable future. I used to spend a lot more time tinkering with configs that could be wiped out by a failed Windows Update.