I think 進捗状況を逐次お知らせします。is better. ご進捗状況 is a honorific, it is used to express "your progress" like ご進捗状況をお知らせいただければ幸いです。＝We hope you let us know your progress. お～します is a humble expression. You can also say 進み具合を逐一御報告いたします. But 進み具合 is a casual word. 進捗状況 is a stiff word. So 進捗状況を逐次お知らせします。is more formal.