My general advice (unofficial, although it has received some support from other editors and hasn't been officially condemned)
When you are in the situation of having submitted to one category only, and you realize it's not the right category, then submit -- once -- to what you think IS the right category.
Doing this may help the editors find the right category more quickly, and won't waste much of their time.
Now, after you've done that, if you AGAIN think you've made a mistake, then just stop: the editors will find the right category -- that's our job. And with a track record of not helping them, you can guess you aren't cut out to handle taxonomy in the large: and you're going to begin to look like a shotgun spammer real soon. All of your submittals except one will be systematically deleted; we may accidentally delete that last one also, causing extra delays for you and possibly causing the loss of a good listing for us. That WOULDN'T help.
As so often in real life, the basic kindergarten rules offer a reliable guide. What would happen if everyone acted like I'm about to? How would I feel if people treated my mailbox like I'm about to treat the ODP queue? Would I consider it fair if all my competitors did this but I wasn't allowed to?
If you can look your mother in the face and answer those questions, then go ahead and do it: you won't need to worry about what anyone will think, you'll already know.
More complex (and much more unusual) situations may require more than kindergarten-level logic, but the kindergarten-level rules still apply. If you've already pestered the editors with submittals, a new submittal may still be helpful, but ONLY if it enables the editor to easily clean up some of the inappropriate submittals. ("Easily" means "without having to look at the site or hunt through categories for the other submittals.")
