As others have said, the rehabilitation aspect is dubious. It depends on what the person “experiences” for that length of time. If there’s therapy in time-dilation-space then sure go right ahead and sign me up as well. I’ll just Goku-it up in my chamber of time and space and work some shit out in time for my morning shit. But you and I both know it ain’t going to work that way. Prisoners will just be trapped in an empty void with only their own thoughts to keep them company, most likely rendering them insane. An infinite solitary confinement is just plain torture.