I have no desire to 'graduate'. [That would allow him a chance to die, yes, but it would also be a victory for the Admiral and he has dedicated centuries to fighting against what gods want.]

The... temporary pairings provide an opportunity for wardens to learn the names of a range of inmates and practice their speeches on the different types. It is also a distraction, you are here because you want something and this provides an illusion that something is being accomplished. On some level it is also a type of check, to make sure inmates have someone to 'revive' them or to be held in some sort of position of responsibility if they create more than the usual degree of trouble. [He hates the barge in between periods of not caring but he's not stupid and he can't ignore everything, however much he tries.]

How worthwhile any of that is, depends on what you desire.