Amending the 1040 before the CR1 interview?

Hi! Petitioner here.

Context: Originally, when I filed my taxes with a CPA and on my own for the past few years, the total income for each year fall 50% below the i864p poverty guideline. But I showed my tax documents to a different CPA today. He realized I've been filing wrong all these years. My total income for every year should actually be around $36000 for every year, which is $10,000 above the poverty line! So, the current CPA recommended that I amend all my federal tax returns for the past few years and send the amended forms to the NVC so that I will not need a joint sponsor.

However, I've been DQ'd just yesterday, my original 3 tax forums have already been submitted to the NVC, and the NVC requested that "may" need to find a joint sponsor. I have not received the interview letter yet.

Questions: 
1) Would it be wise to follow the current CPA's advice?
2) Won't the Interviewer be suspect of the amendments? Or will the interviewer accept the amendments?
3) Should I contact NVC regarding my situation? Or is there a likelihood that they'll see my situation as a red flag?
4) Will amending tax forms delay the NVC process by months and months?
5) Even having earned $36000 per year for all three years and its anticipated for 2025, should I still have a joint sponsor?

Thanks in advance for answering  these questions!