I admit to having missed that footnote, but I think I am intending to make a subtly different point here, which is that not only does a mismatch with ancestral environment undercut the “our ancestors didn’t have sunscreen” argument, but rather the strong correlation between UV intensity and skin color indicates that this is not a weak selection pressure and getting exactly the right amount of sun is probably kind of a big deal.
Especially if it is true that it’s just vitamin D that was imposing pressure towards lighter skin and we can get the same effect that through dietary supplementation.
Is this assuming these people are bad enough at English that they cannot write at all, or just that they have bad grammar and aren’t as good at expressing themselves? For people I’ve seen who are fluent but obviously non-native speakers, I think writing in the target language and then asking an LLM to make it sound idiomatic and in the right register but without sounding like an LLM works better than asking for a direct translation
I noticed a friend of mine suddenly had much better English in some contexts, but not in a way that would have been noticable if I didn’t know how normal way of writing.
Another thing I’ve done myself is to have a standard prompt or skill that says to explain all changes, give options and then translate the new version back into my native language so that I can be more likely to pick up on nuances I may be missing. This has helped me catch a lot of meaning changes in the grammar clean up phase, plus it helps me learn a bit more about the kinds of mistakes I’m making.