Suggested edits have a long grace period that permits additional changes. As a matter of fact, the grace period only ends once the review is complete.
There are no records kept of edits made to a suggested edit—not even moderators can see this information.
I was going to say this doesn't happen often, and I assume that is true, but without hard data I leave it at that. Still, I don't think it is much of a problem. A review gets completed once it receives two approve or two reject votes (and few other corner cases). If we assume good faith on the part of both reviewers and suggester, then in the end we will have with better content—and that is what matters.
Creating a new review task doesn't seem necessary. In the slim chance that the two reject votes are reached even after you made an edit, you could wonder if the edit was really all that awesome. There is no penalty for reviewers when they chose reject and the edit is approved later on. And a rejected edit can be re-submitted later if the analysis is that the first revision contributed to the rejection.
Nothing needs to change for now.
