The good news is that veteran designer Rob Markham has submitted two Civil War battle games for a new series. These are Antietam and Seven Pines in his Burnished Rows of Steel series. The scale and ease-of-play is in the neighborhood of the Nappy 20 series, so that should fill the slot for a playable ACW games line nicely.
Oh nice. Seven Pines is an underrepresented battle for sure. Looking forward to developments.