I wouldn't try the I-601A waiver anyway. Why? Because right now there are millions of undocumented persons in the U.S. that are married to U.S. Citizens and even have U.S. Citizen children but they do not leave because they are afraid to be stuck outside for 10 years. What has changed is that before, a person had to leave the U.S. and spend around 15 months or so while waiting for their appointment at the U.S. Embassy or Consulate
in their home country and then HOPE that they got approved, but the change is that now they say that the same person can apply inside the U.S., supposedly get a pre-approval, but they still have to leave the U.S. and present themselves to the U.S. Embassy or Consulate. So why do I think it may be a trap? Because it could very easily be a way to just get those many millions of people to finally leave the U.S. and once they are outside, they can still be denied the waiver even though they have a "pre-approval". I just don't trust that. So I would just wait for immigration
reform to come out. I know that may not happen for awhile, but it is the safer thing to do.
If you still want to go forward with it, if they have denied it, you will need to file an I-290B and ask them to reconsider or appeal the decision and show evidence that you did you leave the U.S. Here is an official link to the things that you can use to prove physical presence in the U.S.:
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