I would like to see DLCs get reworked with new features and QOL improvements to make them worth their money, heres some ideas
-improve UVs on the school and library models, this is just a graphical thing, but the school and library models have so many UV problems that cause slanted floorboards, stretched textures, textures rotated 90 degrees the wrong way etc, if these were fixed the models would look a lot better
-Add paint cans into the school DLC, there could be paint cans in the art room and the attic of the school, throwing these at the janitor would cause him to go and shower in the bathroom of the school (which already has an area for him to shower that was cut)
Distractions in the Library DLC, there could be boxes, chairs, bottles leftover from visitors, cans etc, that when thrown will make a loud impact sound that alerts the librarian from anywhere in the library, the downside to this would be that the librarian would go into a hunting state after checking where the distraction was, and if she sees the player, she immediately will start chasing them,
Improve the Librarian AI, the Librarian AI is quite broken right now and causes her to mess up when chasing the player, the way it SHOULD work is if the librarian spots you running or jumping or vaulting, she should go into chasing mode, if she loses you, she will hunt for the player, and that will make her more sensitive to sound, after a minute, she goes back into idling mode, where if she sees the player, she will only chase if they are running, jumping, vaulting etc.
These ideas and a few more suggested by others, along with major bug fixes, could really make the DLCs worth the time and money spent on them, hope this helped.