Thanks for reply. However with regard to the years, what I meant is for example 2/3 years, would be the equivalent of say 10 years ageing to the body. So the cost of 10 years general prison - food, shelter, operational cost, problems with inmates causing violence etc vs plugging in a crio-tube for much less time, to effectively steal years from them as punishment - to me would be less cost. The drugs would be administered by the tube itself to bring on the aging process more quickly effectively damaging the body more quickly. The whole dream thing, drugs could be used to bring on bad dreams as kind of punishment or the story could just be that the tubes are designed so you dream heavily to keep the mind stable and active for long periods of time. Thus possibly explaining the events of last two films as vivid dreams.
Just an idea I had few years ago, realise won't be for everyone. I think given there has been suggestion they won't discount the other two films may not work. But would be a way you could introduce and older Ripley, Hicks, as their current characters if that's the direction they take.