I should start by saying I got what I wanted, except it would be nice if I could choose "It's OK but I'm lazy and want to add one of the template comments".
The system admonished me but still really added the comment. Like I said, what I wanted, but inconsistent nonetheless.
In fact gnat was fixing it, via Review > Edit, while I was being lazy, so I'd delete the comment except that I'm mentioning it here on meta. Gnat has mentioned in the comments that his review edit was rejected too! I see that as a separate bug. He changed it manually afterwards.