Crates, thanks for your post - and also for getting an earlier one of yours deleted! I think it's really tricky for people who've done the puzzle to keep significant info, however slight, out of their posts - hence the 'inadvertent' referred to in the Listener thread opener.
I think Norah's MO - err on the side of caution - is a sensible option, it's better to be safe than sorry. Norah also made a good point about not wanting to thwart beginners. I'm sure many experienced hands would like more solvers to enjoy the full fun, glory, challenge of Listeners - a little encouragement and yes, a little help, could go a very long way.