I really don’t want a massive grid! I just want ONE ad position in the content of the blog post. It’s not an unusual thing to have, even in a blog post – most bloggers are trying to make money from their blogs, and that’s the whole reason the 468 width banner exists.
I can fully understand you don’t want users creating spammy-looking sites which reflect badly on your theme, but I think blocking the ability to add a small advertising banner is is taking things a wee bit too far. However now I know what to do, I can easily put that bit of code in the child theme so don’t feel you have to code it.