Whenever you file for a I-751 waiver, you need to show that you entered into the underlying marriage in good faith, and show the bona fides of the marriage. It doesn't matter if the adjudication is before the USCIS or the Immigration Judge.
You should definitely hire a good immigration lawyer who will be able to analyze the situation and guide you through this process. Good luck!
Being successful before USCIS or an IJ would depend on whether you can show that the marriage was entered into in good faith, even though a separation immediately followed. I'd recommend you consult with and hire a reputable and experienced immigration attorney to help you with your waiver. Good luck.
[This answer is for general purposes only; it does not constitute advice and does not establish an attorney-client relationship.]
Why are you being so pessimistic? Your I-751 can still be won at the USCIS level by invoking one or more of the various exceptions that exist to the joint filing requirement. But you are certainly not going to solve your problem or get your case approved if you file the I-751 on your own by relying on general responses from a blog such as this one. Hire an immigration attorney now. Before it gets too late and you made lots of mistakes.
Behar Intl. Counsel 619.234.5962 Kindly be advised that the answer above is only general in nature cannot be construed as legal advice, given that not enough facts are known. It is your responsibility to retain a lawyer to analyze the facts specific to your particular situation in order to give you specific advice. Specific answers will require cognizance of all pertinent facts about your case. Any answers offered on Avvo are of a general nature only, and are not meant to create an attorney-client relationship.
There are a exceptions to the general rule involving I-751s but you should contact an attorney for help.
The answer provided here is general in nature and does not take into account other factors that may need to be reviewed for a more precise answer. You should consult with an immigration attorney before taking any action. The answer here is not intended to create an attorney-client relationship.