The President caved in and ordered illegal immigrant families held together. That action was unfortunate but politically unavoidable, one supposes. A problem is the length of time required to settle asylum applications (>20 days).
I think I have an answer for the Flores consent decree saying you can't hold minors for more than 20 days. The answer is to hold their illegal immigrant parents and invite those detained parents to keep their children with them if that is the parents' desire. The children are not being "held," but being permitted to accompany their parents who are being held. This permission is extended as a courtesy in the interest of keeping families together.
One presumes most parents will have them stay. Some late adolescents will go, but they aren't the small children over whom everybody anguishes.