Family Based Green Card Spill Over to Employment Base Green Card

Hello ,
I have question about spill over visas which is transferred Family based unused visas to Employment base category. My family based immigration petition I-130 was approved in 2010 waiting to get my green card. My sibling filed for me and get the petition approved. I am currently on H1b in USA and legally living here since 8 years.
Is there any legal ground to challenge USCIS on spill over visas . Spill over Green Card should only transfer which are unused. I am right here where they are processing , considered unused family visa to Employment based category. Processing is still going on for spilled over visa from family based category to employment based category. Is there any legal ground challenging this situation as they dont have to process my green card overseas. I am right here in USA and it will be same for them to process my Family based green card as they are processing employment base green card.
Please advise me if I have any legal ground on this rule.