With an RFE on my I-526 petition, what is the best process for EB-5 approval?

I-526 processing is done entirely by mail. No phone calls or meetings. Planning for your green card application will be done best with the help of an immigration attorney who can discuss options and timelines. But right now, no one is getting anything done in one month.

They will not grant a face-to-face for clarification and you can assume many years to get the conditional green card to be able to reside here. There may be a nonimmigrant visa to allow you to come sooner while awaiting permanent residency.

USCIS does not provide for in-person interviews at the request of an applicant. Be sure you understand and respond to USCIS in a detailed and informed manner since denial rates are fairly high. Also, unless you are experienced in EB-5, you need to have qualified professionals guiding you through the process. USCIS is not going to bypass the National Visa Center background checks stage, in fact, that is the second bottleneck even after approval. If you were able to enter the U.S., after approval, on a dual intent-type visa, then you might be eligible to adjust status in the U.S. But they are taking many months to process work and travel permits so you might not be able to work in the EB-5 business for months even after filing an adjustment.

No, to be issued a visa, it has to be forwarded abroad, or if you are in the U.S. in legal status, you can file to adjust status.