Aha! Good on yer for thinking outside the box like that. I never noticed the missing gibberish, but in retrospect it's a clear pattern.

When I first encountered the beast (New York Magazine, I think it was, in the late 50s or so) they weren't called double-dactyls yet but rather went by the name "Higgledy -Piggledies." It never occurred to me that that was a negotiabe part of the format.

I think I disagree with the first stipulation, too - nothing reasonable requires that they be one sentence, and not a paragraph or even a conversation.

I'll keep your practice in mind for the future!