The devs have confirmed that they're getting rid of the Rio Chapter for 3.0. I suggested a while ago that one way they could keep the Rio Chapter would be to simply make it a unique releasable/puppet for for the Alamo Chapter (or any Traditionalist Chapter) to prop up from the Rio Republic. "We'll let the the Republic keep some of its autonomy as a Chapter and your job is to guard south of the Rio Grande". The devs keeps shooting it down. Maybe you could put the Rio Chapter back through your mod?