The guidelines specifically say not to submit a site that is "under construction". But there are four reasonably-likely cases now:
(A) The site has already been reviewed. It wasn't listable then, and isn't listable now.
(B) The site hasn't been reviewed yet, the suggestion is still waiting review.
(C) The site has been reviewed, in, say, the last month. It wasn't listable then, but would be listable now.
(D) The site was reviewed, say, three or six months ago. It wasn't listable then, but would be listable now.
In cases (A) and (B), for different reasons, there is no need to do anything, and nothing useful you could do.
In case (C), the site could be resubmitted. But don't, now. Here's why. Say I'm an editor, looking through recent suggestions. I see a site that has been submitted, and has just been reviewed by some active and respected editor, who noted that it wasn't listable. I could (a) review the site again, (b) leave it for later, (c) curse the submitter for a serial spammer, and delete the suggestion as a duplicate of an already-reviewed suggestion. Which, do you think, is most likely?
In case (D), again I have three possibilities. But now action (a) is NOT obviously a waste of time now, and the editor might well review it again. (There's no guarantee, as I read the social contract, of more than one review, though. But editors' mission is to build a directory, not to "fulfil a social contract to website owners." So whatever is likely to build the directory, is likely to get done.)
So my recommendation, based on the way things work, would be: (1) Make sure the site is REALLY listable NOW, because the odds on a THIRD review AREN'T good. (2) WAIT. Three months at least, preferably six months. (3) Suggest the site again.
Now case (C) above CAN'T be true, because if the site had been reviewed in the last six months, it would have been listed if it WAS listable, and if it had been reviewed earlier than that--well, that would be case (D).
