In the face of the evidence that SHU does not actually keep those dangerous people you refer to from doing harm, and actually makes them more likely to harm others when they get out of prison, what exactly are you arguing? The current system obviously doesn’t work. You may not yet have a good suggestion, but the current system is causing harm and needs to be stopped immediately. And as I pointed out already, simply eliminating or reducing SHU without replacing it with anything else has not resulted in more violence. So it seems there is no need for an alternative solution at all. Remove something that is harmful and not helpful. What is your objection exactly?