Is it ok to eat basil leaves spotted with rust?
There are no raised bumps underneath! Leaves were fIne until the end of summer!
Unless you know for sure what the infectious agent is, I wouldn't eat the leaves. And of course, certainly don't eat if you've sprayed with a chemicals. This article on basil diseases may be useful to you: https://www.gardeningknowhow.com/edible/herbs/basil/basil-diseases.htm