I would really love a mod where staff can place something through a wall (that the prisoner can't go through either). For example canteens and prisoner uniforms. It's really for prisons that have isolated prisoner areas and they don't interact with each other.
In real life a canteen serving table would be something you can't climb over ideally and the staff from the kitchen can place items without having to go all the way out and around to the front of the serving table and be among all the prisoners.

Another idea: say you have a classroom but you split it up so each prisoner has access to their section of the classroom but not all of it, by dividing it up but still allowing the teacher to teach through the divisions of the class room. I've tried doing this using the walls that aren't walls that divide rooms, but it didn't work, only the first division is functional and it considers the walls traversable so they'll share things like canteens despite not being able to go through the walls. You have the visitation booths that divide rooms this way, but since guards can escort prisoners through staff areas to these areas it's unnecessary.
These are really specific expectations but I really believe it would expand what's possible and makes the prison more efficient.