Thank you, but the reason I posted again was that the link you kindly provided did not address the consequences to derivatives in such a change, but only to the beneficiary adult child. "Effect on adult children: If you filed a petition for your unmarried adult children (age 21 or older) when you were an LPR, NVC will change the visa category from family second preference (F2B) to family first preference (F1). However, under a federal law called the Child Status Protection Act (CSPA), visa applicants can “opt out” of conversion to the F1 visa category and remain an F2B visa applicant. This may be beneficial because sometimes the wait time for an F2B visa is shorter than the wait time for an F1 visa. When you naturalize and become a U.S. citizen, you should check the Visa Bulletin to see if it would be helpful for your adult unmarried child to remain in the F2B category. (Applicants keep the priority date of their F2B petition when it converts to the F1 visa category.) Applicants who want to opt-out of conversion to the F1 category must submit a request using these guidelines:" so far I have not been able to find a credible source that deals directly with the affects such a change has on the derivatives. I realize that there is no significant impact on the beneficiary.